OBJECTIVES LABS, DEMONSTRATIONS, AND ACTIVITIES TECHNOLOGY RESOURCES
Compression guide:To shorten instructionbecause of time limitations,omit the Chapter Lab.
12 The Periodic TableChapter Planning Guide
Chapter Opener
333A Chapter 12 • The Periodic Table
OSP Lesson Plans (also in print)TR Bellringer Transparency*
TR P109 The Periodic Table of theElements*
CRF SciLinks Activity*gVID Lab Videos for Physical Science TE Internet Activity, p. 341gCD Science Tutor
TE Demonstration Grouping, p. 336g TE Activity Element Sampling, p. 337 ◆g
TE Activity Looking for Gaps, p. 339a SE Quick Lab Conduction Connection, p. 340 ◆g
CRF Datasheet for Quick Lab* TE Activity Element Game, p. 340b TE Activity Elements Everywhere, p. 341g SE School-to-Home Activity Patterns of Symbols,
p. 342g SE Model-Making Lab Create a Periodic Table,
p. 352 ◆g
CRF Datasheet for Chapter Lab*
Section 1 Arranging the Elements• Describe how Mendeleev arranged elements in the
first periodic table.• Explain how elements are arranged in the modern
periodic table.• Compare metals, nonmetals, and metalloids based
on their properties and on their location in theperiodic table.
• Describe the difference between a period anda group.
OSP Lesson Plans (also in print)TR Bellringer Transparency*
TR LINK TOLINK TO LIFE SCIENCELIFE SCIENCE L79 TheSkeleton*
SE Internet Activity, p. 348g CD Interactive Explorations CD-ROM
Element of SurprisegCD Science Tutor
TE Connection Activity Math, p. 347g TE Connection Activity History, p. 348a SE Connection to Biology Water Treatment, p. 349g LB Whiz-Bang Demonstrations Waiter, There’s Carbon in
My Sugar Bowl!*b LB Inquiry Labs The Chemical Side of Light*g LB Long-Term Projects & Research Ideas
It’s Element-ary*a SE Science in Action Math, Social Studies, and Language
Arts Activities, pp. 358–359g
PACING • 45 min pp. 344–351Section 2 Grouping the Elements• Explain why elements in a group often have similar
properties.• Describe the properties of the elements in the groups
of the periodic table.
OSP Parent Letter ■
CD Student Edition on CD-ROM CD Guided Reading Audio CD ■
TR Chapter Starter Transparency*VID Brain Food Video Quiz
SE Start-up Activity, p. 335 ◆gpp. 334–343PACING • 135 min
CRF Vocabulary Activity*g SE Chapter Review, pp. 354–355g
CRF Chapter Review* ■g
CRF Chapter Tests A* ■g, B*a, C*s SE Standardized Test Preparation, pp. 356–357g
CRF Standardized Test Preparation*gCRF Performance-Based Assessment*gOSP Test Generator, Test Item Listing
CHAPTER REVIEW, ASSESSMENT, ANDSTANDARDIZED TEST PREPARATION
PACING • 90 min
Online and Technology Resources
Visit go.hrw.com foraccess to Holt OnlineLearning, or enter thekeyword HP7 Homefor a variety of freeonline resources.
This CD-ROM package includes:• Lab Materials QuickList Software• Holt Calendar Planner• Customizable Lesson Plans• Printable Worksheets
• ExamView® Test Generator• Interactive Teacher’s Edition• Holt PuzzlePro®
• Holt PowerPoint® Resources
STANDARDS CORRELATION SKILLS DEVELOPMENT RESOURCES SECTION REVIEW AND ASSESSMENT CORRELATIONS
Chapter 12 • Chapter Planning Guide 333B
CRF Directed Reading A* ■b, B*s IT Interactive Textbook* Struggling ReadersStruggling Readers
CRF Vocabulary and Section Summary* ■g
SE Reading Strategy Mnemonics, p. 336g SE Connection to Language Arts Hidden Help, p. 337g TE Reading Strategy Discussion, p. 338g TE Support for English Language Learners, p. 338 TE Inclusion Strategies, p. 339 SE Math Practice Percentages, p. 341g
SE Reading Checks, pp. 336, 337, 340, 342g TE Homework, p. 337g TE Reteaching, p. 342b TE Quiz, p. 342g SE Section Review,* p. 343 ■g
TE Alternative Assessment, p. 343gCRF Section Quiz* ■g
UCP 1; SAI 2; SPSP 5; HNS 1, 2,3; PS 1b; Chapter Lab: UCP 1;SAI 1, 2
CRF Directed Reading A* ■b, B*s IT Interactive Textbook* Struggling ReadersStruggling Readers
CRF Vocabulary and Section Summary* ■g
SE Reading Strategy Paired Summarizing, p. 344g TE Inclusion Strategies, p. 344 TE Support for English Language Learners, p. 345 SE Connection to Environmental Science Recycling Aluminum,
p. 347g MS Math Skills for Science Checking Division with Multiplication*g SS Science Skills Finding Useful Sources*gCRF Reinforcement Worksheet Placing All Your Elements on the
Table*bCRF Critical Thinking Believe It or Not*a
SE Reading Checks, pp. 345, 346, 347, 348,350g
TE Homework, p. 349a TE Reteaching, p. 350b TE Quiz, p. 350g SE Section Review,* p. 351 ■ g
TE Alternative Assessment, p. 351gCRF Section Quiz* ■g
ST 2; PS 1b, 3e
SE Pre-Reading Activity, p. 334gOSP Science Puzzlers, Twisters & Teasersg
National ScienceEducation Standards
UCP 1, 2; SAI 1; ST 2; SPSP 5;HNS 1, 3
CRF Chapter Resource File SS Science Skills Worksheets IT Interactive TextbookOSP One-Stop Planner MS Math Skills for Science Worksheets * Also on One-Stop Planner
SE Student Edition LB Lab Bank CD CD or CD-ROM ◆ Requires advance prepTE Teacher Edition TR Transparencies VID Classroom Video/DVD ■ Also available in Spanish
KEY
Maintained by the NationalScience Teachers Association.See Chapter Enrichment pagesthat follow for a complete listof topics.
www.scilinks.orgCheck out Current Sciencearticles and activities byvisiting the HRW Web siteat go.hrw.com. Just typein the keyword HP5CS12T.
• Lab Videos demonstratethe chapter lab.
• Brain Food Video Quizzeshelp students review thechapter material.
ClassroomVideos
Holt Lab GeneratorCD-ROM
Search for any lab by topic, standard,difficulty level, or time. Edit any labto fit your needs, or create your ownlabs. Use the Lab Materials QuickListsoftware to customize your labmaterials list.
• Guided Reading Audio CD(Also in Spanish)
• Interactive Explorations• Virtual Investigations• Visual Concepts• Science Tutor
ClassroomCD-ROMs
Planning ResourcesTEST ITEM LISTINGPARENT LETTERLESSON PLANS
Visual ResourcesBELLRINGER
TRANSPARENCIES TEACHING TRANSPARENCIESCHAPTER STARTER
TRANSPARENCY
TEACHING TRANSPARENCIESCONCEPT MAPPING
TRANSPARENCY
TEST ITEM LISTING
Copyright © by Holt Rinehart and Winston All rights reserved
The World of ScienceMULTIPLE CHOICE
1. A limitation of models is thata. they are large enough to see.b. they do not act exactly like the things that they model.c. they are smaller than the things that they model.d. they model unfamiliar things.Answer: B Difficulty: I Section: 3 Objective: 2
2. The length 10 m is equal toa. 100 cm. c. 10,000 mm.b. 1,000 cm. d. Both (b) and (c)Answer: B Difficulty: I Section: 3 Objective: 2
3. To be valid, a hypothesis must bea. testable. c. made into a law.b. supported by evidence. d. Both (a) and (b)Answer: B Difficulty: I Section: 3 Objective: 2 1
4. The statement "Sheila has a stain on her shirt" is an example of a(n)a. law. c. observation.b. hypothesis. d. prediction.Answer: B Difficulty: I Section: 3 Objective: 2
5. A hypothesis is often developed out ofa. observations. c. laws.b. experiments. d. Both (a) and (b)Answer: B Difficulty: I Section: 3 Objective: 2
6. How many milliliters are in 3.5 kL?a. 3,500 mL c. 3,500, 000 mLb. 0.0035 mL d. 35,000 mLAnswer: B Difficulty: I Section: 3 Objective: 2
7. A map of Seattle is an example of aa. law. c. model.b. theory. d. unit.Answer: B Difficulty: I Section: 3 Objective: 2
8. A lab has the safety icons shown below. These icons mean that you should weara. only safety goggles. c. safety goggles and a lab apron.b. only a lab apron. d. safety goggles, a lab apron, and gloves.Answer: B Difficulty: I Section: 3 Objective: 2
9. The law of conservation of mass says the tot al mass before a chemical change isa. more than the total mass after the change.b. less than the total mass after the change.c. the same as the total mass after the change.d. not the same as the total mass after the change.Answer: B Difficulty: I Section: 3 Objective: 2
10. In which of the following areas might you find a geochemist at work?a. studying the chemistry of rocks c. studying fishesb. studying forestry d. studying the atmosphereAnswer: B Difficulty: I Section: 3 Objective: 2
TEACHER RESOURCE PAGE
Lesson Plan
Section: Waves
PacingRegular Schedule: with lab(s):2 days without lab(s):2 days
Block Schedule: with lab(s): 1 1/2 days without lab(s): 1 day
Objectives1. Relate the seven properties of life to a living organism.
2. Describe seven themes that can help you to organize what you learn aboutbiology.
3. Identify the tiny structures that make up all living organisms.
4. Differentiate between reproduction and heredity and between metabolismand homeostasis.
National Science Education Standards CoveredLSInter6: Cells have particular structures that underlie their functions.
LSMat1: Most cell functions involve chemical reactions.
LSBeh1:Cells store and use information to guide their functions.
UCP1:Cell functions are regulated.
SI1: Cells can differentiate and form complete multicellular organisms.
PS1: Species evolve over time.
ESS1: The great diversity of organisms is the result of more than 3.5 billion yearsof evolution.
ESS2: Natural selection and its evolutionary consequences provide a scientificexplanation for the fossil record of ancient life forms as well as for the strikingmolecular similarities observed among the diverse species of living organisms.
ST1: The millions of different species of plants, animals, and microorganismsthat live on Earth today are related by descent from common ancestors.
ST2: The energy for life primarily comes from the sun.
SPSP1: The complexity and organization of organisms accommodates the needfor obtaining, transforming, transporting, releasing, and eliminating the matterand energy used to sustain the organism.
SPSP6: As matter and energy flows through different levels of organization ofliving systems—cells, organs, communities—and between living systems and thephysical environment, chemical elements are recombined in different ways.
HNS1: Organisms have behavioral responses to internal changes and to externalstimuli.
This CD-ROM includes all of theresources shown here and thefollowing time-saving tools:
• Lab Materials QuickListSoftware
• Customizable lesson plans
• Holt Calendar Planner
•The powerfulExamView® TestGenerator
Chapter Resources
Dear Parent,
Your son's or daughter's science class will soon begin exploring the chapter entitled “The
World of Physical Science.” In this chapter, students will learn about how the scientific
method applies to the world of physical science and the role of physical science in the
world. By the end of the chapter, students should demonstrate a clear understanding of the
chapter’s main ideas and be able to discuss the following topics:
1. physical science as the study of energy and matter (Section 1)
2. the role of physical science in the world around them (Section 1)
3. careers that rely on physical science (Section 1)
4. the steps used in the scientific method (Section 2)
5. examples of technology (Section 2)
6. how the scientific method is used to answer questions and solve problems (Section 2)
7. how our knowledge of science changes over time (Section 2)
8. how models represent real objects or systems (Section 3)
9. examples of different ways models are used in science (Section 3)
10. the importance of the International System of Units (Section 4)
11. the appropriate units to use for particular measurements (Section 4)
12. how area and density are derived quantities (Section 4)
Questions to Ask Along the Way
You can help your son or daughter learn about these topics by asking interesting questions
such as the following:
• What are some surprising careers that use physical science?
• What is a characteristic of a good hypothesis?
• When is it a good idea to use a model?
• Why do Americans measure things in terms of inches and yards instead of centimeters
and meters ?
333C Chapter 12 • The Periodic Table
12
Would YouBelieve . . . ?Suppose someone told you that the small animalshown above—a yellow-spotted rock hyrax—isgenetically related to an elephant. Impossible,you say? But it’s true! Even though this animallooks more like a rabbit or a rodent, scientistshave determined through DNA studies that theclosest relatives of the hyrax are aardvarks, seacows, and elephants. Biologists have uncoveredsimilar genetic links between other seeminglydifferent species.
Scientists have also discovered that manydifferent-looking elements, like those shown atright, actually have common properties. For almost150 years, scientists have organized elements byobserving the similarities (both obvious and notso obvious) between them. One scientist inparticular—a Russian named Dmitri Mendeleev(MEN duh LAY uhf )—organized the known elementsin such a way that a repeating pattern emerged.Mendeleev actually used this patternto predict the properties of elementsthat had not even been discovered! Hismethod of organization becameknown as the periodic table.
The modern periodic table isarranged somewhat differently thanMendeleev’s, but it is still a useful toolfor organizing the known elements andpredicting the properties of elementsstill unknown. Read on to learn aboutthe development of this remarkabletable and the patterns it reveals.
The Periodic Table CHAPTER STARTER
Although solid iodine and liquid bromine havevery different appearances, they have similarchemical properties.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
The Periodic Table BELLRINGER TRANSPARENCY
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section: Arranging the ElementsThink of all the ways a deck of cards could be laidout so that the cards form some sort of identifiablepattern. Illustrate your answers in your science
journal. Write out as many different patterns as youcan.
Section: Grouping the ElementsThink about the following: How do you know a birdis a bird? a kangaroo is a kangaroo? a shark is ashark? What characteristics of each animal help youto tell them apart? How does this apply to elements?
Record your answers in your science journal.
140.1
232.0
140.9
231.0
144.2
238.0
(145)
(237)
150.4
(244)
6.9
23.0
39.1
85.5
132.9
9.0
24.3
40.1
87.6
137.3
(226)
45.0
88.9
138.9
(227)
47.9
91.2
178.5
(261)
50.9
92.9
180.9
(262)
52.0
95.9
183.8
(266)
54.9
(98)
186.2
(264)
55.8
101.1
190.2
(277)
58.9
102.9
192.2
(268)
1.0
Praseodymium
Rutherfordium
Molybdenum
Lithium
Sodium
Potassium
Rubidium
Cesium
Cerium
ThoriumProtactinium
Neodym
ium
Uranium
Promethium
Neptunium
Samarium
Plutonium
Beryllium
Magnesium
Calcium
Strontium
Barium
Radium
Scandium
Yttrium
Lanthanum
Actinium
Titanium
Zirconium
Hafnium
Vanadium
Niobium
Tantalum
Dubnium
Chrom
ium
Tungsten
Seaborgium
Manganese
Technetium
Rhenium
Bohrium
Iron
Ruthenium
Osm
ium
Hassium
Cobalt
Rhodium
Iridium
Meitnerium
Hydrogen
Li
V
NaKRb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
ScYLa
Ac
Ti
Zr
Hf
Rf
Nb
Ta
Db
Cr
Mo
WSg
Mn
Re
Bh
IrO
s
Ce
Th
Pr
Pa
NdU
PmNp
SmPu
Fe
Ru
Hs
Co
Rh
Mt
H
Tc
31119375587
5890
5991
6092
6193
6294
41220385688
21395789
224072
104
234173
105
244274
106
254375
107
26447677
108
2745
109
1
Group 3
Group 4
Group 5
Group 6
Group 7
Group 8
Group 9
Group 1
Group 2
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Lanthanides
Background
Metals
Metalloids
Nonm
etals
Chemical sym
bol
Solid
Liquid
Gas
6CThe color of thechem
ical sym-
bol indicates thephysical state atroom
temperature.
Carbon is a solid.
The background color indicates thetype of elem
ent. Carbon is a nonm
etal.
These elements are placed
below the table to allow
the table to be narrower.
A column of
elements is called
agroup or
family.
Ato
mic n
um
ber
Ch
emical sym
bo
l
Elemen
t nam
e
Ato
mic m
ass
A row of
elements is
called aperiod.
Values in parentheses are the mass num
bers of thoseradioactive elem
ents’ most stable or m
ost comm
on isotopes.
Periodic
Table o
f the
Elements
Each square on the table includes anelem
ent’s name, chem
ical symbol,
atomic num
ber, and atomic m
ass.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
152.0
(243)
157.2
(247)
158.9
(247)
162.5
(251)
164.9
(252)
167.3
(257)
168.9
(258)
173.0
(259)
175.0
(262)
58.763.5
65.469.7
72.674.9
79.079.9
83.8
27.028.1
31.032.1
35.539.9
10.812.0
14.016.0
19.020.2
4.0
106.4107.9
112.4114.8
118.7121.8
127.6126.9
131.3
195.1
(281)(272)
197.0200.6
204.4207.2
209.0(209)
(210)(222)
(285)(289)
(288)(284)
Europium
Am
ericium
Gadolinium
Curium
Terbium
Berkelium
Dysprosium
Californium
Holm
ium
Einsteinium
Erbium
Fermium
Thulium
Mendelevium
Ytterbium
Nobelium
Lutetium
Lawrencium
Nickel
Copper
ZincG
alliumG
ermanium
Arsenic
SeleniumB
romine
Krypton
Alum
inumSilicon
PhosphorusSulfur
Chlorine
Argon
Boron
Carbon
Nitrogen
Oxygen
FluorineN
eon
Helium
PalladiumSilver
Cadm
iumIndium
TinA
ntimony
TelluriumIodine
Xenon
Darm
stadtiumU
nununium
PlatinumG
oldM
ercuryThallium
LeadB
ismuth
PoloniumA
statineR
adon
Ununbium
Ununquadium
Ununpentium
Ununtrium
Eu
Am
Gd
Cm
Tb
Bk
Dy
Cf
Pd
Ag
Cd
InSn
SbT
eI
Xe
Pt
Ds
Uu
u
Au
Hg
Tl
Pb
Bi
Po
At
Rn
Ho
Es
Er
Fm
Tm
Md
Yb
No
Lu
Lr
Ni
Cu
Zn
Ga
Ge
As
SeB
rK
r
Al
Si
PS
Cl
Ar
BC
NO
FN
e
He
Uu
bU
uq
Uu
pU
ut
2829
3031
3233
3435
36
1314
1516
1718
56
78
910 2
4647
4849
5051
5253
54
7879
8081
8283
8485
86
110111
6395
6496
6597
6698
6799
68
100
69
101
70
102
71
103
112114
115113
Group 13
Group 14
Group 15
Group 16
Group 17
Group 18
Group 10
Group 11
Group 12
The discovery of elements
113, 114, and 115 has beenreported but not confirm
ed.
This zigzag linerem
inds you where
the metals, nonm
etals,and m
etalloids are.
The names and three-letter sym
bols of elements are tem
porary. Theyare based on the atom
ic numbers of the elem
ents. Official nam
es andsym
bols will be approved by an international com
mittee of scientists.
The Periodic TableTEA
CHIN
G TR
AN
SPAR
ENCY
The Periodic Table of the Elements
P109
arranged in
is a chart of
metalloids
in which thenumber of
that areclassified as
rowscalled
columnscalled
increases fromleft to right
The Periodic Table CONCEPT MAPPING TRANSPARENCY
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Use the following terms to complete the concept map below:elements, periods, metals, electrons, nonmetals, periodic table,familiesThe Skeleton
Copyright © by Holt, Rinehart and Winston. All rights reserved.
TEACH
ING
TRA
NSPA
REN
CY
Protection
Your heartand lungs are protectedby ribs, your spinal cordis protected by verte-brae, and your brain isprotected by the skull.
StorageB
ones storem
inerals that help yournerves and m
usclesfunction properly. Longbones store fat that canbe used for energy.
Movem
ent
Skeletalm
uscles pull on bonesto produce m
ovement.
Without bones, you
would not be able to sit,
stand, walk, or run.
Blood
Cell Formation
Some of your bones
are filled with a special
material that m
akesblood cells. This m
aterialis called
marrow
.
Femur
Pelvicgirdle
Vertebralcolum
n
Patella
Tibia
Fibula
Ulna
Radius
Skull
Ribs
Clavicle
Hum
erus
L79
Chapter: Body Organization and Structure
SAMPLE SAMPLE SAMPLE
Meeting Individual Needs
Review and Assessments
Labs and Activities
DIRECTED READING A VOCABULARY ACTIVITY REINFORCEMENT
INQUIRY LABS
STANDARDIZED TEST PREPARATIONCHAPTER TEST BCHAPTER REVIEWSECTION QUIZ
SCILINKS ACTIVITY
MARINE ECOSYSTEMS
Go to www.scilinks.com. To find links relatedto marine ecosystems, type in the keywordHL5490. Then, use the links to answer thefollowing questions about marine ecosys-tems.
1. What percentage of the Earth’s surface iscovered by water?
2. What percentage of the Earth’s water is found in the oceans?
3. What is the largest animal on Earth?
4. Describe an ocean animal.
Name Class Date
SciLinks ActivityActivity
Developed and maintained by theNational Science Teachers Association
Topic: Reproductive SystemIrregularitiesSciLinks code: HL5490
WHIZ-BANGDEMONSTRATIONS
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Name Class Date
Vocabulary ActivityActivity
Getting the Dirt on the SoilAfter you finish reading Chapter: [Unique Title], try this puzzle! Use the clues belowto unscramble the vocabulary words. Write your answer in the space provided.
1. the breakdown of rock intosmaller and smaller pieces:AWERIGNETH
2. layer of rock lying beneath soil:CROKDEB
3. type of crop that is plantedbetween harvests to reduce soilerosion: CROVE
4. action of rocks and sedimentscraping against each other andwearing away exposed surfaces:SABRONIA
5. a mixture of small mineral frag-ments and organic matter: LISO
6. rock that is a source of soil:PRATEN CORK
7. type of reaction that occurs whenoxygen combines with iron toform rust: oxidation
8. type of weathering caused byphysical means: CLEMANIACH
9. the chemical breakdown of rocksand minerals into new substances: CAMILCHETHEARIGWEN
10. layers of soil, to a geologist:SNORHIZO
11. the uppermost layer of soil:SPOTOIL
12. process in which rainwater car-ries dissolved substances fromthe uppermost layers of soil to thebottom layers: HELANCIG
13. small particles of decayed plantand animal material in soil:MUUSH
14. the process in which wind, water,or ice moves soil from one location to another: ROOSINE
15. the methods humans use to takecare of soil:OSIL VASETONRICON
LONG-TERM PROJECTS & RESEARCH IDEAS
DATASHEETS FOR QUICKLABS
DATASHEETS FOR QUICK LABS
VOCABULARY AND SECTION SUMMARY
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section: EnergIn the space provided, write the letter of the description that best matches theterm or phrase.
______ 1. building molecules that can be used asan energy source. or breaking down moleculesin which energy is stored
______ 2. the process by which light energy is convertedto chemical energy
______ 3. an organism that uses sunlight or inorganicsubstances to make organic compounds
______ 4. an organism that uses sunlight or inorganicsubstances to make organic compounds
______ 5. an organism that consumes food to get energy
______ 6. the process of getting energy from food
In the space provided, write the letter of the term or phrase that best completeseach statement or best answers each question.
Name Class Date
Section QuizAssessment
a. photosynthesis
b. autotroph
c. heterotroph
d. cellular respiration
e. metabolism
f. cellular respiration
______ 7. Which of the following mostclosely resembles cellularrespiration?a. warm water moving
through copper pipesb. people movimg alomg a
escalatorc. mixing different foods in
a blenderd. logs burning in a fire
______ 8. An organism’s reproductivecells, such as sperm or eggcells, are called?a. genesb. chromosomesc. gamates.d. zygotes.
______ 9. An organism’s reproductivecells, such as sperm or eggcells, are called?a. genesb. chromosomesc. gamates.d. zygotes.
______10. Which of the following mostclosely resembles cellularrespiration?a. warm water moving
through copper pipesb. people movimg alomg a
escalatorc. mixing different foods in
a blenderd.
logs burning in a fire
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Section: ExploringTHAT’S SCIENCE!
1. How did James Czarnowski get his idea for the penguin boat, Proteus?Explain.
2. What is unusual about the way that Proteus moves through the water?
MATTER + AIR ➔ PHYSICAL SCIENCE
3. What do air, a ball, and a cheetah have in common?
4. What is one question you will answer as you explore physical science?
5. Chemistry and physics are both fields of . Chemists
study the different forms of and how they interact.
and how it affects are
studied in physics.
Identify the field of physical science to which each of the following descriptionsbelongs by writing physics or chemistry in the space provided.
_______________________ 6. how a compass works
_______________________ 7. why water boils at 100°C
_______________________ 8. how chlorine and sodium combine to form table salt
_______________________ 9. why you move to the right when the car you are inturns left
Directed Reading A
Name Class Date
Skills Worksheet
DIRECTED READING B
Section: ExploringTHAT’S SCIENCE!
1. How did James Czarnowski get his idea for the penguin boat, Proteus?Explain.
2. What is unusual about the way that Proteus moves through the water?
MATTER + AIR ➔ PHYSICAL SCIENCE
3. What do air, a ball, and a cheetah have in common?
Directed Reading B
Name Class Date
Skills Worksheet
Section: UniqueVOCABULARY
In your own words, write a definition of the following term in the space provided.
1. scientific method
2. technology
3. observation
Name Class Date
Vocabulary & NotesSkills Worksheet
Name Class Date
ReinforcementSkills Worksheet
The Plane TruthComplete this worksheet after you finish reading the Section: [Unique SectionTitle]
You plan to enter a paper airplane contest sponsoredby Talkin’ Physical Science magazine. The personwhose airplane flies the farthest wins a lifetime sub-scription to the magazine! The week before the con-test, you watch an airplane landing at a nearbyairport. You notice that the wings of the airplane haveflaps, as shown in the illustration at right. The paperairplanes you’ve been testing do not have wing flaps.What question would you ask yourself based on these observations? Write yourquestion in the space below for “State the problem.” Then tell how you could usethe other steps in the scientific method to investigate the problem.
1. State the problem.
2. Form a hypothesis.
3. Test the hypothesis.
4. Analyze the results.
5. Draw conclusions.
Flaps
Copyright © by Holt, Rinehart and Winston. All rights reserved.
CRITICAL THINKING
A Solar Solution
Name Class Date
Critical Thinking Skills Worksheet
Joseph D. Burns
Inventors’ Advisory Consultants
Portland, OR 97201
Dear Mr. Burns,I’ve got this great idea for a new product called the BlissHeater. It’s a portable, solar-powered space heater. The heater’s design includes these features:•T
he heater will be as longas an adult’s arm and aswide as a
packing box.
•T
he heater will have aglass top set at an angleto catch the sun’s rays.
•T
he inside of the heaterwill be dark colored toabsorb solar heat.If you think my idea will work, I will make the Bliss
Heaters right away without wasting time and money on test-ing and making models. Please write back soon with youropinion.
SECTION REVIEW
Section: UniqueKEY TERMS
1. What do paleontologist study?
2. How does a trace fossil differ from petrified wood?
3. Define fossil.
UNDERSTANDING KEY IDEAS
Name Class Date
Section ReviewSkills Worksheet
Copyright © by Holt, Rinehart and Winston. All rights reserved.
[UniqueMULTIPLE CHOICE
In the space provided, write the letter of the term or phrase that best completeseach statement or best answers each question.
______ 1. Surface currents are formed by a. the moon’s gravity. c. wind.b. the sun’s gravity. d. increased water density.
______ 2. When waves come near the shore, a. they speed up. c. their wavelength increases.b. they maintain their speed. d. their wave height increases.
______ 3. Longshore currents transport sediment a . out to the open ocean. c. only during low tide.b. along the shore. d. only during high tide.
______ 4. Which of the following does NOT control surface currents?a. global wind c. Coriolis effectb. tides d. continental deflections
______ 5. Whitecaps break a. in the surf. c. in the open ocean.b. in the breaker zone. d. as their wavelength increases.
______ 6. Most ocean waves are formed by a . earthquakes. c. landsides.b. wind. d. impacts by cosmic bodies.
______ 7. Which factor controls surface currents? a. global winds c. continental deflectionb. the Coriolis effect d. all of the above
______ 8. Streamlike movments of ocean water far below the surface arecalleda. jet currents c. surface currents.b. Coriolis currents. d. deep currents.
______ 9. When the sunlit part of the moon that can be seen from Earthgrows larger, it is a. waxing. c. in the new moon phase.b. waning. d. in the full moon phase.
______10. The Milky Way is thought to be a. an elliptical galaxy. c. a spiral galaxy.
Name Class Date
Chapter Test BAssessment
Copyright © by Holt, Rinehart and Winston. All rights reserved.
READING
Read the passages below. Then, read each question that follows the passage.Decide which is the best answer to each question.
Passage 1 adventurous summer camp in the world. Billy can’twait to head for the outdoors. Billy checked the recommendedsupply list: light, summer clothes; sunscreen; rain gear; heavy,down-filled jacket; ski mask; and thick gloves. Wait a minute! Billythought he was traveling to only one destination, so why does heneed to bring such a wide variety of clothes? On further investiga-tion, Billy learns that the brochure advertises the opportunity to“climb the biomes of the world in just three days.” The destinationis Africa’s tallest mountain, Kilimanjaro.
______ 1. The word destination in this passage means A camp B vacation.C place. D mountain.
______ 2. Which of the following is a FACT in the passage? F People ski on Kilimanjaro.G Kilimanjaro is Africa’s tallest mountain.H It rains a lot on Kilimanjaro.J The summers are cold on Kilimanjaro.
______ 3. Billy wondered if the camp was advertising only one destination afterhe read the brochure, which said thatA the camp was the most adventurous summer camp in the world. B he would need light, summer clothes and sunscreen.C he would need light, summer clothes and a heavy, down-filled
jacket.D the summers are cold on Kilimanjaro.
Name Class Date
Standardized Test PreparationAssessment
PERFORMANCE-BASEDASSESSMENT
OBJECTIVEDetermine which factors cause some sugar shapes to break down faster than others.
KNOW THE SCORE!As you work through the activity, keep in mind that you will be earning a gradefor the following:
• how you form and test the hypothesis (30%)
• the quality of your analysis (40%)
• the clarity of your conclusions (30%)
ASK A QUESTIONSWhy do some sugar shapes erode more rapidly than others?
MATERIALS AND EQUIPMENT
Name Class Date
Performanced-Based AssessmentAssessment SKILL BUILDER
Using Scientific Methods
• 1 regular sugar cube • 90 mL of waterCopyright © by Holt, Rinehart and Winston. All rights reserved.
USING VOCABULARY
1. Define biome in your own words.
2. Describe the characteristics of a savanna and a desert.
3. Identify the relationship between tundra and permafrost.
4. Compare the open-water zone and the deep-water zone.
5. Use each of the following terms in an original sentence: plankton, littoralzone, and estuary.
6. Describe how marshes and swamps differ.
Name Class Date
Chapter ReviewSkills Worksheet
SCIENCE PUZZLERS, TWISTERS & TEASERS
CHAPTER TEST A
[UniqueMULTIPLE CHOICE
In the space provided, write the letter of the term or phrase that best completeseach statement or best answers each question.
______ 1. Surface currents are formed by a. the moon’s gravity. c. wind.b. the sun’s gravity. d. increased water density.
______ 2. When waves come near the shore, a. they speed up. c. their wavelength increases.b. they maintain their speed. d. their wave height increases.
______ 3. Longshore currents transport sediment a . out to the open ocean. c. only during low tide.b. along the shore. d. only during high tide.
______ 4. Which of the following does NOT control surface currents?a global wind c Coriolis effect
Name Class Date
Chapter Test AAssessment
CHAPTER TEST C
[UniqueMULTIPLE CHOICE
In the space provided, write the letter of the term or phrase that best completeseach statement or best answers each question.
______ 1. Surface currents are formed by a. the moon’s gravity. c. wind.b. the sun’s gravity. d. increased water density.
______ 2. When waves come near the shore, a. they speed up. c. their wavelength increases.b. they maintain their speed. d. their wave height increases.
______ 3. Longshore currents transport sediment a . out to the open ocean. c. only during low tide.b. along the shore. d. only during high tide.
______ 4. Which of the following does NOT control surface currents?a global wind c Coriolis effect
Name Class Date
Chapter Test CAssessment
Chapter 12 • Chapter Resources 333D
Periodic Crime1. This is an eyewitness account of a crime recently committed.
Which element committed the crime?
“He was definitely a metal, but really soft, like you could cut himwith a knife. As he ran past us, we squirted him with a water gun.He burst into flame! It was unbelievable. We almost had him cor-nered, but he pulled out a vile of chlorine gas and in the blink ofan eye, he disappeared. All that was left was a pile of table salt.”
Elements in the Round2. Moving from the outside of the circle to the center of the circle,
choose one letter from each ring to find the names of eight com-mon elements. Write the names of the elements on the lines pro-vided. Each letter will be used only once.
Name _______________________________________________ Date ________________ Class______________
SCIENCE PUZZLERS, TWISTERS & TEASERS12
The Periodic Table
CHAPTER
I
The history of the periodic table is like a detective story that spans many centuries.Although most of the elements on Earth have been around for billions of years,scientists have had to do some sleuthing to find each element’s unique identity.
The ancient Greeks knew nine elements, including gold, sulfur, copper, and car-bon. These elements, which are found in almost pure form as minerals, are callednative elements. In 1669, Hennig Brand was the first scientist to actively search forand isolate an element. It was phosphorus. After that, many other scientists lookedfor other elements. In fact, seventy-four other elements were discovered between1737 (cobalt) and 1925 (rhenium). The contributions of history’s “elemental”detectives have helped build the modern periodic table—a chemist’s best friend.
Periodic Changes1. Find older versions of the periodic table in textbooks and
encyclopedias from the last 75 years. How has the periodictable changed? How is it the same? On a modern periodictable, label the dates when 10 of the elements were discov-ered. How are new elements discovered and added to theperiodic table? Write a report and make a poster display toillustrate your findings.
Research Ideas2. Each element has a story to tell. Pick one element from
the periodic table to research. When was it discovered?How did the element get its name? What are its proper-ties? What are its uses? Is the element found in any com-mon materials? How is it obtained? Report your findingsin the form of a story written from the element’s point of view.
3. That’s a killer element! Some transition metals, includingcadmium, nickel, mercury, and lead, are hazardous tohuman health. Find out more about how these elementsare used and why they are dangerous. Write a brochurethat outlines the precautions one should take to preventpoisoning people and polluting the environment whenusing these metals.
4. Did you know that your blood is full of metal? Your bodyneeds iron to stay healthy. Most of the iron in the body is found in hemoglobin, the chemical in red blood cellsthat carries oxygen and carbon dioxide in your blood.Find out more about the properties of elemental iron andthe compound hemoglobin. How much iron do you needdaily? Where do you get iron in your diet? Write yourfindings in the form of a magazine article.
Name ___________________________________________________ Date _________________ Class _____________
PROJECT
STUDENT WORKSHEET62
It’s Element-ary
PH
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HELPFUL HINT
Try searching for thename of the metal, plus the word toxicity,poisoning, or elemental.For example, you mightsearch for cadmium tox-icity or lead poisoning.
John Dalton’sTable of Elements,1808
PH
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TEACHER-LED DEMONSTRATION
DEMO
55
Purpose
Students will draw a connection betweenorganic matter and its fundamental ele-ment, carbon, as they view a spectacularchemical reaction. They will learn aboutchemical changes and prove that sugarcontains carbon.
Time Required
10–15 minutes
Safety Information
Use extreme caution while performing thisdemonstration. Sulfuric acid is extremelycaustic and can damage body tissue. Thevapors can also cause severe eye and lungirritation and may cause tissue damage.The beaker and its contents get very hot,as well. Minimize risk by performing thisdemonstration under a fume hood or out-side, and use protective goggles, a faceshield, and gloves. Be sure students stay atleast 1–2 m away from the beaker at alltimes. Handle the chunk of carbon pro-duced in the experiment with tongs, as itwill still be coated with sulfuric acid.
What to Do
1. Find a suitable location for this demon-stration. Make sure there is enoughroom for the students to stand 1–2 mfrom the reaction and still see clearly.
2. Place 30 mL of sugar in the beaker.
3. Slowly add 5–10 mL of sulfuric acid tothe sugar.
4. Stand back and watch! As clouds ofsteam and smoke are produced, stu-dents should observe carbon “growing”out of the beaker.
Explanation
When the sulfuric acid (H2SO4) combinedwith the sugar (C12H22O11), a chemicalchange took place. As the sugar was dehy-drated, energy was released in the form ofheat. Water vapor and sulfur dioxide es-caped as gases. The black substance left inthe beaker is carbon.
Discussion
Use the following questions as a guide toencourage class discussion:
• Does the substance remaining in thebeaker resemble any substance you’veseen before? (The substance resemblescoal.) Explain that coal is a form of carbon.
• What ingredient used in the demonstra-tion may have contained carbon? (Sugar)How do you know? (All living things con-tain carbon. Sugar is the byproduct of a liv-ing thing, a plant.)
• Did you observe a chemical or physicalchange? (Chemical) How do you know?(A new substance was formed.)
MATERIALS
• 100 mL beaker• 30 mL of sugar• 5–10 mL of sulfuric acid• a face shield• chemical-resistant gloves• tongs
Brian BurnightBig Bear Middle SchoolBig Bear Lake, California
TEACHER PREP
CONCEPT LEVEL
CLEAN UP
E A S Y H A R D
Lab Ratings
Waiter, There’s Carbon in My Sugar Bowl STUDENT WORKSHEET
LAB
20
PH
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Name Date Class
How do scientists know what elements make up theouter layers of the sun? After all, they can’t justscoop up a bucketful of sun and bring it back to thelaboratories on Earth for analysis. There must besome indirect way of determining the compositionof the sun’s outer layers. Scientists can tell what el-ements make up the outer layers of the sun by look-ing at sunlight through a device called aspectroscope. Like a prism, a spectroscope breaks uplight into different wavelengths.
In fact, every element has its own “light finger-print,” which means that each element gives off dis-tinctively colored bands of light! Shortly, you’ll havea chance to correlate bands of light with the el-ements because Agent Spectra is about to send you a secret message made of light! To help you crackthe code, Agent Spectra sent you the decoder cardshown at right. Now all you need to do is constructa spectroscope and wait for the light signals. As soonas you identify the elements, you will read and inter-pret Agent Spectra’s secret message!
The Chemical Side of Light
ObjectiveDetermine the chemical composition of various light sources,and crack the code!
Construct a Spectroscope1. Trace two circles onto the card using the end of the tube.
2. Cut the two circles slightly larger than the tube’s diameter.
3. Mark a 2 � 2 cm square in the center of one circle.
4. Cut the square from the circle so you have a square hole.
5. Tape the diffraction grating over the hole.
6. Tape the circle with the diffraction grating over one openingof the cardboard tube so that light must passthrough the grating to enter the tube.
7. Bring the other circle to your teacher, whowill cut a thin slit in its center.
8. Place the circle with the slit against the openend of the tube. Hold the circle in place asyou look at a light source through the otherend of the spectroscope.
MATERIALS
• cardboard tube• index card• scissors• metric ruler• diffraction grating• masking tape• set of crayons or col-
ored pencils• light source
Substance Code
Na for want of a
K the
Hg was lost
Ne horse
Sr nail
Cu shoe
H � C rider
Decoder Card
Copyright © by Holt, Rinehart and Winston. All rights reserved.Copyright © by Holt, Rinehart and Winston. All rights reserved.
TEACHER RESOURCE PAGE
Name Class Date
Reaction to StressQuick Lab DATASHEET FOR QUICK LAB
BackgroundThe graph below illustrates changes that occur in the membrane potential of aneuron during an action potential. Use the graph to answer the followingquestions. Refer to Figure 3 as needed.
Analysis1. Determine about how long an action potential lasts.
2. State whether voltage-gated sodium, chanels are open or closed at point A.
3. State whether voltage-gated potassium channels are open or closed atpoint B.
4. Critical Thinking Recognizing Relationships What causes the menberneotential to become less negative at point A?
5. Critical Thinking Recognizing Relationships What causes the membranepotential to become more negative at point B?
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Answer here.
Answer here.
Answer here.
Answer here.
Answer here.
Using Scientific Methods
For a preview of available worksheets covering math, science, and reading skills, see pages T26–T33. All of these resources are also on the One-Stop Planner®.
GENERAL
GENERALGENERAL
GENERAL
GENERAL
GENERAL
GENERAL
SPECIAL NEEDS
SPECIAL NEEDS GENERAL
GENERAL
GENERAL
GENERAL
SAMPLE
SAMPLE SAMPLE
SAMPLE SAMPLE
SAMPLE
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DATASHEETS FORCHAPTER LABS
Teacher’s NotesTIME REQUIRED
One 45-minute class period.
RATINGTeacher Prep–3Student Set-Up–2Concept Level–2Clean Up–2
MATERIALS
The materials listed on the student page are enough for a group of 4–5 students.Large, dried beans of any kind will work well in this exercise.
SAFETY CAUTION
Remind students to review all safety cautions and icons before beginning this labactivity.
Using Scientific MethodsSkills Practice Lab DATASHEET FOR CHAPTER LAB
TEACHER RESOURCE PAGE
1 2 3 4Easy Hard
Jason MarshMontevideo High
and Country School
SAMPLE
DATASHEETS FORLABBOOK
Teacher’s NotesTIME REQUIRED
One 45-minute class period.
Does It All Add Up?Skills Practice Lab DATASHEET FOR LABBOOK LAB
TEACHER RESOURCE PAGE
Jason MarshMontevideo High
SAMPLE
Chapter Enrichment
333E Chapter 12 • The Periodic Table
This Chapter Enrichment provides relevant and
interesting information to expand and enhance
your presentation of the chapter material.
Arranging the ElementsBefore the Periodic Table• Elements such as gold, sil-
ver, tin, copper, lead, and mercury have been known for thousands of years.
• The first modern discovery of an element was in 1669 when German alchemist Hennig Brand discovered phosphorus by precipitating it out of urine.
• Sixty-three elements had been discovered by 1869. As more elements were discovered, scientists recog-nized similarities and patterns in the properties of elements, and some scientists proposed classification schemes.
• In 1817, Johann Döbereiner (1780–1849) realized that calcium, strontium, and barium have similar proper-ties and that the atomic weight of strontium is about halfway between those of the other two elements.
Is That a Fact!◆ The first comprehensive arrangement of the elements
showing the periodicity of chemical and physical properties was published in 1862 by French geologist A. E. Beguyer de Chancourtois. De Chancourtois posi-tioned the elements on a cylinder in order of increas-ing atomic weight. When he arranged the elements so that there were 16 on the cylinder per turn, he noted that closely related elements lined up vertically.
The Law of Triads• In 1829, after discovering the triad chlo-
rine, bromine, and iodine and the triad lithium, sodium, and potassium, Döbereiner proposed his law of triads: In nature, there are triads of elements in which the middle element has an atomic weight that is the average of the atomic weights of the other two elements in the triad.
• Between 1829 and 1858, several scientists worked on the idea of triads. They discovered that the chemical relationship extended beyond groups of three. Fluorine was added to the halogen group; oxygen, sulfur, sele-nium, and tellurium were grouped into a family; and nitrogen, phosphorus, arsenic, antimony, and bismuth were grouped into a family.
The Law of Octaves• English chemist John Newlands (1837–1898) noticed
that several pairs of similar elements were separatedin atomic weight by some multiple of 8. In 1864, Newlands proposed his law of octaves: Elements whose atomic weights differ by some multiple of 8 have similar properties.
The Father of the Periodic Table?• Two chemists, a German named Lothar Meyer (1830–1895)
and a Russian named Dmitri Mendeleev (1834–1907), produced—completely independently of each other—nearly identical tables of the elements at almost the same time.
• Unfortunately for Meyer, Mendeleev’s table was published in 1869, a year before Meyer’s table, and Mendeleev received credit for the first modern periodic table of the elements.
Is That a Fact!◆ Mendeleev’s (and Meyer’s) table was a pioneering
development because it allowed scientists to predict the existence of elements that had not yet been dis-covered. Most scientists were skeptical at first. But then gallium was discovered in 1875 and was found to closely match Mendeleev’s predictions.
12
Grouping the ElementsWhat Goes Where?• Mendeleev’s table showed that the elements could be
grouped into periods, but it didn’t explain why. As themodern periodic table took shape, scientists realizedthat the underlying order was based on atomic struc-ture, namely, the number of protons in each atom.
• The known elements fall into three main categories,or classes: metals, metalloids (semiconductors), andnonmetals.
The Noble Gases• One of the most important additions to the periodic
table was the addition of the noble gases. Englishphysicists John William Strutt, Lord Rayleigh(1842–1919), and William Ramsay (1852–1916)discovered argon in 1894.
• In 1895, Ramsay discovered that helium exists onEarth. Then, in 1898 Ramsay (and his assistant,Morris W. Travers) discovered three more noblegases—neon, krypton, and xenon.
• Radon was discovered by German scientist FriedrichErnst Dorn (1848–1916) in 1900.
Is That a Fact!◆ Argon makes up about 1% of Earth’s atmosphere, but
argon remained completely undetected until 1894because it is unreactive under normal conditions.
The Modern Periodic Table• In the early 1940s, Glenn Seaborg and his team worked
on the Manhattan Project, the United States’s secreteffort to make the atomic bomb. Seaborg and his col-leagues discovered the element plutonium in 1940.
• In the 1940s and 1950s, Seaborg’s team synthesizedand identified all transuranic elements that haveatomic numbers 94 to 102. Seaborg also rearrangedthe periodic table by placing the actinide series belowthe lanthanide series. This change was the last majorchange to the modern periodic table.
Transuranic Elements• Elements whose atomic numbers are greater than 92,
known as transuranic elements, have been made in labo-ratories by bombarding heavy elements with neutronsor other subatomic particles. Plutonium (atomic num-ber 94) occurs in small amounts in nature. Scientistscontinue to make heavier transuranic elements, so theperiodic table continues to change.
• All transuranic elements are radioactive, and someexist for only short amounts of time before theydecay into other, lighter elements.
For background information about teaching strategies and
issues, refer to the Professional Reference for Teachers.
Topic: Periodic TableSciLinks code: HSM1125
Topic: MetalsSciLinks code: HSM0947
Topic: Alkali MetalsSciLinks code: HSM0043
Topic: Halogens and Noble GasesSciLinks code: HSM0711
Topic: MetalloidsSciLinks code: HSM0946
Topic: NonmetalsSciLinks code: HSM1043
Visit www.scilinks.org and enter the SciLinks code formore information about the topic listed.
SciLinks is maintained by the National Science Teachers Associationto provide you and your students with interesting, up-to-date links thatwill enrich your classroom presentation of the chapter.
Developed and maintained by theNational Science Teachers Association
Chapter 12 • Chapter Enrichment 333F
Standards Correlations
OverviewTell students that this chapterwill help them learn about theperiodic table of the elements.The chapter describes some ofthe history of the developmentof the table and describes char-acteristics of each group ofelements on the table.
Assessing PriorKnowledgeStudents should be familiarwith the following topics:
• chemical and physicalprop erties
• atomic number
IdentifyingMisconceptionsAs students learn the material inthis chapter, some of them maybe confused about how to tellwhether an element is a metal,a metalloid, or a nonmetal.Remind students as they studythe chapter that the zigzag lineshown on most periodic tablesis a helpful tool but that theelements are classified based ontheir properties.
National Science Education Standards
The following codes indicate the National Science EducationStandards that correlate to this chapter. The full text of thestandards is at the front of the book.
Chapter OpenerUCP 1, 2; SAI 1; ST 2; SPSP 5; HNS 1, 3
Section 1 Arranging the ElementsUCP 1; SAI 2; SPSP 5; HNS 1, 2, 3; PS 1b
Section 2 Grouping the ElementsST 2; PS 1b, 3e
Chapter LabUCP 1; SAI 1, 2
Chapter ReviewPS 1b
Science in ActionUCP 5; HNS 1, 3
12
334 Chapter 12 • The Periodic Table
PRE-READINGPRE-READING
The Periodic Table
About the
You already know or have heard aboutel ements on the periodic table, such asoxygen, carbon, and neon. Neon gas was discovered in 1898. In 1902, a French engi-neer, chemist, and inventor named GeorgesClaude made the fi rst neon lamp. In 1910,Claude made the fi rst neon sign, and in 1923,he introduced neon signs to the United States.Now, artists such as Eric Ehlenberger useglass and neon to create interesting works ofart, such as these neon jellyfi sh.
Three-Panel Flip ChartBefore you read the chapter,create the FoldNote entitled
“Three-Panel Flip Chart” described in theStudy Skills section of the Appendix.Label the flaps of the three-panel flipchart with “Metal,” “Nonmetal,” and“Metalloid.” As you read the chapter,write informationyou learn about eachcategory under theappropriate flap.
SECTION
Elements are organized onthe periodic table accordingto their properties.
12
1 Arranging the Elements. . . . . . 336
2 Grouping the Elements . . . . . . 344
START-UPPlacement PatternIn this activity, you will identify the pattern your teacher used to create a new classroom seating arrangement.
Procedure1. Draw a seating chart for the new classroom
arrangement that your teacher gave to you. Write the name of each of your classmates in the place on the chart that corresponds to his or her seat.
2. Write information about yourself, such as your name, date of birth, hair color, and height, in the space that represents you on the chart.
3. Gather the same information about the people near you, and write it in the spaces on the chart.
Analysis1. From the information you gathered, identify a
pattern that might explain the order of people in the chart. Collect more information if needed.
2. Test your pattern by gathering information from a person you did not talk to before.
3. If the new information does not support your pattern, reanalyze your data and collect more information to determine another pattern.
Chapter 12 • The Periodic Table 335
START-UPSTART-UP vv
Teacher’s Notes: To do this activity, you will need to make a seating chart before the class period. Possible organizational ideas for the arrangement include placing students by birth date, by height, or alpha-betically by their first names. This activity can be repeated by using different patterns, includ-ing patterns that are periodic.
Answers
1. Students should be able to describe the new seating pattern and, using the information they collected, explain how they arrived at their result.
3. Some students may have diffi-culty determining the new seating pattern. Encourage other students to assist them in analyzing the data and finding the pattern.
Would YouBelieve . . . ?Suppose someone told you that the small animalshown above—a yellow-spotted rock hyrax—isgenetically related to an elephant. Impossible, you say? But it’s true! Even though this animallooks more like a rabbit or a rodent, scientistshave determined through DNA studies that theclosest relatives of the hyrax are aardvarks, seacows, and elephants. Biologists have uncoveredsimilar genetic links between other seemingly different species.
Scientists have also discovered that many different-looking elements, like those shown atright, actually have common properties. For almost150 years, scientists have organized elements byobserving the similarities (both obvious and notso obvious) between them. One scientist in particular—a Russian named Dmitri Mendeleev(MEN duh LAY uhf )—organized the known elementsin such a way that a repeating pattern emerged.Mendeleev actually used this patternto predict the properties of elementsthat had not even been discovered! Hismethod of organization becameknown as the periodic table.
The modern periodic table isarranged somewhat differently thanMendeleev’s, but it is still a useful toolfor organizing the known elements andpredicting the properties of elementsstill unknown. Read on to learn aboutthe development of this remarkabletable and the patterns it reveals.
The Periodic Table CHAPTER STARTER
Although solid iodine and liquid bromine havevery different appearances, they have similarchemical properties.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
Chapter Starter TransparencyUse this transparency to help students begin thinking about classifying items based on shared properties.
CHAPTER RESOURCESTechnology
Transparencies • Chapter Starter Transparency
Student Edition on CD-ROM
Guided Reading Audio CD • English or Spanish
Classroom Videos • Brain Food Video Quiz
Workbooks
Science Puzzlers, Twisters & Teasers • The Periodic Table g
READINGSKILLS
READING STRATEGY
Arranging the ElementsSuppose you went to the video store and all the videos were mixed together. How could you tell the comedies from the action movies? If the videos were not arranged in a pattern, you wouldn’t know what kind of movie you had chosen!
Scientists in the early 1860s had a similar problem. At thattime, scientists knew some of the properties of more than 60elements. However, no one had organized the el ements accord-ing to these properties. Organizing the elements according totheir properties would help scientists understand how elementsinteract with each other.
Discovering a PatternDmitri Mendeleev (duh MEE tree MEN duh LAY uhf), a Russianchemist, discovered a pattern to the elements in 1869. First,he wrote the names and properties of the elements on cards.Then, he arranged his cards, as shown in Figure 1, by differentproperties, such as density, appearance, and melting point. Aftermuch thought, he arranged the elements in order of increasingatomic mass. When he did so, a pattern appeared.
✓✓Reading Check How had Mendeleev arranged elements when he noticed a pattern? (See the Appendix for answers to Reading Checks.)
1
Figure 1 By playing “chemical solitaire” on long train rides, Mendeleev organized the elements according to their properties.
What You Will Learn
Describe how Mendeleev arrangedelements in the first periodic table.Explain how elements are arrangedin the modern periodic table.Compare metals, nonmetals, andmetalloids based on their propertiesand on their location in the periodictable.Describe the difference between aperiod and a group.
Vocabularyperiodic periodperiodic law group
Mnemonics As you read thissection, create a mnemonic deviceto help you remember the differencebetween periods and groups.
OverviewThis section gives a short historyof the periodic table. Studentslearn about the modern periodictable and are shown how tointerpret it, and they learn howcharacteristics of elements led toa logical way of grouping theelements.
BellringerAsk students to think of all ofthe ways a deck of cards couldbe laid out so that the cardsform some sort of identifiablepattern. Have students writedown as many patterns asthey can.
Demonstration --------------gGrouping Ask three volunteersto stand at the front of the class.Put two of them together, andask the third to step off to theside for a moment. Ask the classto list characteristics that thetwo students share. List studentresponses on the board.
Now, separate the two students,and ask the third student tostand next to one of the otherstudents. Repeat the exercise.Compare the two lists of charac-teristics. Discuss with the classthe similarities and differencesin the lists. l Visual/Logical Answer to Reading Check
Mendeleev had arranged elements based onincreasing atomic mass.
1
CHAPTER RESOURCES
Chapter Resource File
CRF • Lesson Plan• Directed Reading Ab• Directed Reading Bs
Technology
Transparencies• Bellringer
Workbooks
Interactive Textbook Struggling Readers Struggling Readers
336 Chapter 12 • The Periodic Table
Periodic Properties of the ElementsMendeleev saw that when the elements were arranged in order of increasing atomic mass, those that had similar properties occurred in a repeating pattern. That is, the pattern was peri-odic. Periodic means “happening at regular intervals.” The days of the week are periodic. They repeat in the same order every 7 days. Similarly, Mendeleev found that the elements’ prop-erties followed a pattern that repeated every seven elements. His table became known as the periodic table of the elements.
Predicting Properties of Missing ElementsFigure 2 shows part of Mendeleev’s first try at arranging the elements. The question marks show gaps in the pattern. Mendeleev predicted that elements yet to be found would fill these gaps. He used the pattern he found to predict their properties. Table 1 compares his predictions for one missing element—germanium—with its actual properties. By 1886, all of the gaps had been filled. His predictions were right.
Changing the ArrangementA few elements’ properties did not fit the pattern in Mendeleev’s table. Mendeleev thought that more-accurate atomic masses would fix these flaws in his table. But new atomic mass measurements showed that the masses he had used were cor-rect. In 1914, Henry Moseley (MOHZ lee), a British scientist, determined the number of protons—the atomic number—in an atom. All elements fit the pattern in Mendeleev’s periodic table when they were arranged by atomic number.
Look at the periodic table on the next two pages. All of the more than 30 el ements discovered since 1914 follow the periodic law. The periodic law states that the repeating chemical and physical properties of elements change periodically with the elements’ atomic numbers.
✓Reading Check What property is used to arrange elements in the periodic table?
Figure 2 Mendeleev used question marks to mark some elements that he thought would be found later.
Table 1 Properties of GermaniumMendeleev’spredictions (1869)
Actualproperties
Atomic mass 70 72.6
Density* 5.5 g/cm3 5.3 g/cm3
Appearance dark gray metal gray metal
Melting point* high melting point 937°C
* at room temperature and pressure
periodic describes something that occurs or repeats at regular intervals
periodic law the law that states that the repeating chemical and physical properties of elements change periodically with the atomic numbers of the elements
SKILLHidden Help You may be asked to
memorize some of the chemi-cal symbols. A story or poem that uses the symbols might be helpful. In your science journal, write a short story, poem, or just a few sentences in which the words correspond to and bring to mind the chemical symbols of the first 20 elements.
Section 1 • Arranging the Elements 337
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Element Sampling Obtain sam-ples of several elements that have visibly different properties and that can be displayed safely. Suggestions include:
• sulfur (in powder form)
• helium (in a clear balloon)
• iron (nails)
• aluminum (foil or gutter nails)
• nitrogen (a clear balloon filled with air)
• carbon (charcoal briquettes: some crushed and some whole)
• copper (electrical wire)
• silver (necklace or silver-plated tableware)
You might want to set up sta-tions throughout the room and include several samples at each station. Ask students if they can identify any of the samples, and discuss why they have made a particular identification. Help students identify and label all of the elements. Then, ask students to identify observed characteris-tics, such as color, physical state (solid, liquid, or gas), and luster (shininess or glossiness), for each element. List on the board all the characteristics for each element. Give hints about char-acteristics that students might miss. l Visual
Answer to Reading Check
atomic number
h ----------------------------g
Reviewing Atoms Have students review information that they have learned about atoms by using the following terms to make a concept map: atom, proton, neutron, electron, atomic number, and atomic mass. l Visual/Logical
Is That a Fact!In the late 1800s, scientists began study-ing the color spectra that elements pro-duced when heated. There are patterns within the spectra, and all of the pat-terns are different—no two elements have the same spectrum.
140.1
232.0
140.9
231.0
144.2
238.0
(145)
(237)
150.4
(244)
6.9
23.0
39.1
85.5
132.9
9.0
24.3
40.1
87.6
137.3
(226)
45.0
88.9
138.9
(227)
47.9
91.2
178.5
(261)
50.9
92.9
180.9
(262)
52.0
95.9
183.8
(266)
54.9
(98)
186.2
(264)
55.8
101.1
190.2
(277)
58.9
102.9
192.2
(268)
1.0
Praseodymium
Rutherfordium
Molybdenum
Lithium
Sodium
Potassium
Rubidium
Cesium
Cerium
Thorium Protactinium
Neodymium
Uranium
Promethium
Neptunium
Samarium
Plutonium
Beryllium
Magnesium
Calcium
Strontium
Barium
Radium
Scandium
Yttrium
Lanthanum
Actinium
Titanium
Zirconium
Hafnium
Vanadium
Niobium
Tantalum
Dubnium
Chromium
Tungsten
Seaborgium
Manganese
Technetium
Rhenium
Bohrium
Iron
Ruthenium
Osmium
Hassium
Cobalt
Rhodium
Iridium
Meitnerium
Hydrogen
Li
V
Na
K
Rb
Cs
Fr
Be
Mg
Ca
Sr
Ba
Ra
Sc
Y
La
Ac
Ti
Zr
H f
Rf
Nb
Ta
Db
Cr
Mo
W
Sg
Mn
Re
Bh
IrOs
Ce
Th
Pr
Pa
Nd
U
Pm
Np
Sm
Pu
Fe
Ru
Hs
Co
Rh
Mt
H
Tc
3
11
19
37
55
87
58
90
59
91
60
92
61
93
62
94
4
12
20
38
56
88
21
39
57
89
22
40
72
104
23
41
73
105
24
42
74
106
25
43
75
107
26
44
76 77
108
27
45
109
1
Group 3 Group 4 Group 5 Group 6 Group 7 Group 8 Group 9
Group 1 Group 2
Period 1
Period 2
Period 3
Period 4
Period 5
Period 6
Period 7
Lanthanides
Background
Metals
Metalloids
Nonmetals
Chemical symbol
Solid
Liquid
Gas
6
CThe color of the chemical sym-bol indicates the physical state at room temperature. Carbon is a solid.
The background color indicates the type of element. Carbon is a nonmetal.
These elements are placed below the table to allow the table to be narrower.
A column of elements is called a group or family.
Atomic number
Chemical symbol
Element name
Atomic mass
A row of elements is called a period.
Values in parentheses are the mass numbers of those radioactive elements’ most stable or most common isotopes.
Periodic Table of the ElementsEach square on the table includes an element’s name, chemical symbol, atomic number, and atomic mass.
READINGSTRATEGY -----------------g
Discussion Help studentsrecognize the layout pattern forthe periodic table of the elements.Have them count across the table,group by group, to see that thereare a total of 18 groups. Also, havestudents count the 7 periods. Dis-cuss the triads that Döbereinerfound (see the Chapter Enrich-ment pages at the beginning ofthis chapter), the expanded triads,and the noble gases. Emphasizethat the lanthanides and actinidesare parts of periods 6 and 7 andare not periods by themselves.l Visual
CHAPTER RESOURCESTechnology
Transparencies• P109 The Periodic Table of the Elements
SUPPORT FOR
English LanguageLearnersThe Periodic Table Studentsmay have diffi culty readingsuch a complex table with somany symbols. Use the tablein the book to help studentsas a class recognize the layoutpattern for the periodic tableof elements. Model count-ing across the table groupby group. Ask students tocount across and tell you howmany groups there are. (18)Show that a row of elementsis called a period, and havestudents count the seven pe-riods. Point out that the lasttwo rows, the lanthanides andactinides, are parts of periods6 and 7 and are not periodsby themselves.l Visual/Logical
338 Chapter 12 • The Periodic Table
152.0
(243)
157.2
(247)
158.9
(247)
162.5
(251)
164.9
(252)
167.3
(257)
168.9
(258)
173.0
(259)
175.0
(262)
58.7 63.5 65.4 69.7 72.6 74.9 79.0 79.9 83.8
27.0 28.1 31.0 32.1 35.5 39.9
10.8 12.0 14.0 16.0 19.0 20.2
4.0
106.4 107.9 112.4 114.8 118.7 121.8 127.6 126.9 131.3
195.1
(281) (272)
197.0 200.6 204.4 207.2 209.0 (209) (210) (222)
(285) (289) (288)(284)
Europium
Americium
Gadolinium
Curium
Terbium
Berkelium
Dysprosium
Californium
Holmium
Einsteinium
Erbium
Fermium
Thulium
Mendelevium
Ytterbium
Nobelium
Lutetium
Lawrencium
Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Aluminum Silicon Phosphorus Sulfur Chlorine Argon
Boron Carbon Nitrogen Oxygen Fluorine Neon
Helium
Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Darmstadtium Unununium
Platinum Gold Mercury Thallium Lead Bismuth Polonium Astatine Radon
Ununbium Ununquadium UnunpentiumUnuntrium
Eu
Am
Gd
Cm
Tb
Bk
Dy
Cf
Pd Ag Cd In Sn Sb Te I Xe
Pt
Ds Uuu
Au Hg Tl Pb Bi Po At Rn
Ho
Es
Er
Fm
Tm
Md
Yb
No
Lu
Lr
Ni Cu Zn Ga Ge As Se Br Kr
Al Si P S Cl Ar
B C N O F Ne
He
Uub Uuq UupUut
28 29 30 31 32 33 34 35 36
13 14 15 16 17 18
5 6 7 8 9 10
2
46 47 48 49 50 51 52 53 54
78 79 80 81 82 83 84 85 86
110 111
63
95
64
96
65
97
66
98
67
99
68
100
69
101
70
102
71
103
112 114 115113
Group 13 Group 14 Group 15 Group 16 Group 17
Group 18
Group 10 Group 11 Group 12
The discovery of elements113, 114, and 115 has beenreported but not confirmed.
This zigzag line reminds you where the metals, nonmetals, and metalloids are.
The names and three-letter symbols of elements are temporary. They are based on the atomic numbers of the elements. Official names and symbols will be approved by an international committee of scientists.
Topic: Periodic TableGo To: go.hrw.comKeyword: HN0 PERIODICVisit the HRW Web site for updates on the periodic table.
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Looking for Gaps Have stu-dents consider the progressionof atomic mass across the peri-odic table, where atoms differ innumber by one proton. Ask stu-dents to consider how scientistscan be sure that there are noundiscovered elements betweenhydrogen and uranium.l Logical
Research -------------------------------------------g
PORTFOLIO
What’s New? Scientistsare continually trying to
synthesize new elements. Askstudents to do some research tofind out if any new elementshave been synthesized since thisbook was published. Studentsmay present their findings in ashort report or poster. l Logical
CONNECTION toCONNECTION toHistory---------------------------------------------------g
Not Enough Elements Severalelements, such as gold, silver,copper, tin, and a few others,were known to ancient people.But there weren’t enoughknown el ements to show anypatterns or relationships. Itwasn’t until 1669, the year thatphosphorus was discovered, thatsteps toward creating the mod-ern per iodic table were taken.By 1869, a total of 63 elements(of the 92 that occur in nature)had been discovered. As moreelements were discovered, scien-tists began to see patterns ofproperties among the elementsand began to create classifica-tion schemes.
symbol], and type of element [color of thebackground]) “How many elements areliquid at room temperature?” (2) “Howmany elements are gas at room temper-ature?” (11) “How many elements are metals?” (88) “How many elements aremetalloids?” (6) “How many elementsare nonmetals?” (18) “How many groupsare the elements divided into?” (18) and“How many periods are the elementsdivided into?” (7) l Interpersonalcc
StrategiesStrategiesINCLUSIONINCLUSION
• Learning Disabled• Visually Impaired• Developmentally DelayedHelp students who have trouble under-standing or seeing the periodic tableby writing the questions below on theboard. Read each question aloud. Havestudents work in small groups to answereach one. “What information does eachsquare on the periodic table show?”(atomic number, chemical symbol, elementname, atomic mass, state [color of the
Section 1 • Arranging the Elements 339
The Periodic Table and Classes of ElementsAt first glance, you might think studying the periodic table is like trying to explore a thick jungle without a guide—you can easily get lost! However, the table itself contains a lot of information that will help you along the way.
Elements are classified as metals, non metals, and metal-loids, according to their properties. The number of electrons in the outer energy level of an atom is one characteristic that helps determine which category an element belongs in. The zigzag line on the periodic table can help you recognize which elements are metals, which are nonmetals, and which are metalloids.
MetalsMost elements are metals. Metals are found to the left of the zigzag line on the periodic table. Atoms of most metals have few electrons in their outer energy level. Most metals are solid at room temperature. Mercury, however, is a liquid at room temperature. Some additional information on properties shared by most metals is shown in Figure 3.
✓Reading Check What are four properties shared by most metals?
Conduction Connection
1. Fill a plastic-foam cup with hot water.
2. Stand a piece of copper wire and a graphite lead from a mechanical pencil in the water.
3. After 1 min, touch the top of each object. Record your observations.
4. Which material conducted thermal energy the best? Why?
Properties of MetalsFigure 3
Metals tend to be shiny.You can see a reflection in a mirror because light reflects off the shiny sur-face of a thin layer of silver behind the glass.
Most metals are malleable,which means that they can be flattened with a hammer and will not shatter. Aluminum is flat-tened into sheets to make cans and foil.
Most metals are ductile, whichmeans that they can be drawn into thin wires. All metals are good con ductors of electric current. The wires in the elec-trical devices in your home are made of copper.
Most metals are good conductors of thermal energy. This iron griddle con-ducts thermal energy from a stove top to cook your favoritefoods.
340 Chapter 12 • The Periodic Table
M A T E R I A L S FOR EACH STUDENT
• cup, plastic-foam• graphite, mechanical pencil lead• water, hot• wire, copper, bare, 25 cm long
Safety Caution: Remind stu-dents to review all safety cau-tions and icons before beginning this lab activity.
Teacher’s Notes: The wire should be approximately the same thickness and length as the pencil lead. Test the pro-cedure; adjust the time if necessary.
Answer
4. The wire conducted thermal energy better than the pencil lead did. The wire is made of the metal copper; pencil lead is made of graphite, a form of the nonmetal carbon. Metals conduct thermal energy better than nonmetals do.
Answer to Reading Check
Most metals are solid at room tem-perature, ductile, malleable, and shiny. In addition, they are good conductors of electric current and thermal energy.
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Element Game Make a memory game by using two sets of flip pages. Select 24 elements. Have students write descriptions of these el ements on one set of flip pages and place images of items made from those elements on the second set of flip pages. The element’s name and symbol should be on the back of each page. Have students try to guess the element from its descrip-tion or its picture. Or have students match the pictures with the descriptions. l Visual ee
Is That a Fact!Mercury is the only metal that is liquid at room temperature. It was not thought to be a metal until it was frozen in 1759. The metal cesium is almost a liquid metal. It has a melting point of 28.4°C, so on a hot day, cesium metal would melt into a puddle.
NonmetalsNonmetals are found to the right of the zigzag line on the periodic table. Atoms of most nonmetals have an almost complete set of electrons in their outer level. Atoms of the elements in Group 18, the noble gases, have a complete set of electrons. More than half of the nonmetals are gases at room temperature. Many prop erties of nonmetals are the opposite of the properties of metals, as shown in Figure 4.
MetalloidsMetalloids, also called semiconductors, are the elements that border the zigzag line on the periodic table. Atoms of metal-loids have about half of a complete set of electrons in their outer energy level. Metalloids have some properties of metals and some properties of nonmetals, as shown in Figure 5.
Properties of MetalloidsFigure 5
PercentagesElements are classified as metals, nonmetals, and met-alloids. Use the periodic table to determine the percentage of elements in each of the three categories.
Properties of NonmetalsFigure 4
Nonmetals are poor conductors of thermal energy and electric current. If the gap in a spark plug is too wide, the nonmetals nitrogen and oxygen in the air will stop the spark and a car’s engine will not run.
Nonmetals are not malleable or ductile. In fact, solid non-metals, such as carbon in the graphite of the pencil lead, are brittle and will break or shat-ter when hit with a hammer.
Sulfur, like most non-metals, is not shiny.
Tellurium is shiny, but it is brittle and can easily be smashed into a powder.
Boron is almost as hardas diamond, but it is also very brittle. At high tem-peratures, it is a good conductorof electric current.
Section 1 • Arranging the Elements 341
CONNECTION toCONNECTION toReal World -----------------------------------g
Wiring Homes built between 1965 and 1973 may contain alu-minum wiring, which can be very dangerous. This type of wiring has conductors made of aluminum that may corrode at any connection. Corrosion causes increased electrical resis-tance, which may cause the wire to overheat and start a fire. By 1973, manufacturers had corrected the corrosion problem, so aluminum wiring used after 1973 is much safer. To be safe, people whose homes were wired between 1965 and 1973 should check the wiring and replace it if necessary.
Answers to Math Practice
79% metals, 5% metalloids, and 16% nonmetals
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Elements Everywhere Havestudents check the ingredients of foods and other products in their homes and write down the ingredients that have famil-iar chemical names, such as sodium fluoride. In class, have students place self-adhesive notes containing product names on the corresponding elements on a wall-chart periodic table. l Visual
INTERNETINTERNET vvSequence Board --------------g
For an internet activity related to this chapter, have students goto go.hrw.com and type in the keyword HP5PRTW.
oNaming New Elements Scientists who claim to have made a new element propose a name for it. Names are reviewed and sug-gested by a committee of the International Union of Pure and Applied Chemistry (IUPAC). This committee is made up of sci-entists who are competing with each other to make new elements, so the naming process is sometimes difficult. Eventually, the IUPAC designates one official name, and most scientists then refer to the new element by this official name.
Is That a Fact!Metalloids are also called semiconductorsbecause they conduct electric current more easily than nonmetals do but less easily than metals do. The semiconduc-tors silicon and germanium are extremely important in your everyday life. These elements are used to create microproces-sors for computers.
VK Ti Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36
Ti Ge BrTitanium
22 32 35
Decoding the Periodic TableThe periodic table may seem to be in code. In a way, it is. Butthe colors and symbols will help you decode the table.
Each Element Is Identified by a Chemical SymbolEach square on the periodic table includes an element’s name,chemical symbol, atomic number, and atomic mass. The namesof the elements come from many sources. Some elements, suchas mendelevium, are named after scientists. Others, such ascalifornium, are named after places. Some element names varyby country. But the chemical symbols are the same worldwide.For most elements, the chemical symbol has one or two let-ters. The first letter is always capitalized. Any other letter isalways lowercase. The newest elements have temporary three-letter symbols.
Rows Are Called PeriodsEach horizontal row of elements (from left to right) on theperiodic table is called a period. Look at Period 4 in Figure 6. Thephysical and chemical properties of elements in a row follow arepeating, or periodic, pattern as you move across the period.Properties such as conductivity and reactivity change graduallyfrom left to right in each period.
Columns Are Called GroupsEach vertical column of elements (from top to bottom) on theperiodic table is called a group. Elements in the same groupoften have similar chemical and physical properties. For thisreason, a group is also called a family.
✓Reading Check Why is a group sometimes called a family?
Patterns of SymbolsDivide a sheet of paper intofour columns. Look at theelements whose atomicnumbers are 1 to 20 onthe periodic table. With aparent, find patterns thatdescribe the relationshipbetween the chemical sym-bols and names of elements.In each column, write all ofthe chemical symbols andnames that follow a singlepattern. At the top of eachcolumn, write a sentencedescribing the pattern.
Figure 6 As you move from left to right across a row,the elements become less metallic.
period in chemistry, a horizontalrow of elements in the periodic table
group a vertical column ofelements in the periodic table;elements in a group sharechemical properties
Elements at the left end ofa period, such as titanium,are very metallic.
Elements farther to theright, such as germanium,are less metallic.
Elements at the far-right endof a period, such as bromine,are nonmetallic.
Reteaching -------------------------------------bMalleable and Brittle Reinforcethe meanings of the terms mal-leable and brittle.
Safety Caution: Students shouldwear safety goggles when doingthis activity.
To demonstrate malleability, showstudents small pieces of lead, suchas fishing weights. Use a hammerto shape the lead. To demonstratebrittleness, use a hammer to strikea charcoal briquette wrapped inan old towel. l Visual
Quiz --------------------------------------------------------------------g
1. What does the periodic lawstate? (The chemical and physi-cal properties of elements areperiodic functions of the atomicnumbers of the elements.)
2. Which elements are in thesame group on the periodictable as oxygen is? (sulfur, sele-nium, tellurium, and polonium)
3. List five elements whose sym-bols don’t seem to come fromtheir English names. For exam-ple, Fe is iron. (Others includepotassium, K; sodium, Na; tung-sten, W; copper, Cu; silver, Ag;and gold, Au.)
Answer to Reading Check
Elements in a group often havesimilar chemical and physicalproperties.
Answer to School-to-Home Activity
• One column should include the following: hydro-gen, H; boron, B; carbon, C; nitrogen, N; oxygen,O; fluorine, F; phosphorus, P; and sulfur, S. Thechemical symbol for each of these elements isthe first letter of the name of the element.
• The second column should include the follow-ing: helium, He; lithium, Li; beryllium, Be; neon,Ne; aluminum, Al; silicon, Si; argon, Ar; andcalcium, Ca. The chemical symbol for eachof these elements is the first two letters ofthe name of the element.
• The third column should include the following:sodium, Na; and potassium, K. The chemicalsymbols for these elements do not seem tohave a direct connection to the names of theelements. (In fact, the symbols come from theLatin words natrium [sodium carbonate] andkalium [alkali].)
• The fourth column should include the followingelements: magnesium, Mg; and chlorine, Cl.The chemical symbol for each of these ele-ments consists of the first and third letters ofthe name of the element.
342 Chapter 12 • The Periodic Table
For a variety of links related to thischapter, go to www.scilinks.org
SummarySummary
Review
Using Key Terms
1. In your own words, write a definition for theterm periodic.
Understanding Key Ideas
2. Which of the following elements should be thebest conductor of electric current?
a. germaniumb. sulfurc. aluminumd. helium
3. Compare a period and a group on the periodictable.
4. What property did Mendeleev use to positionthe elements on the periodic table?
5. State the periodic law.
Critical Thinking
6. Identifying Relationships An atom that has117 protons in its nucleus has not yet beenmade. Once this atom is made, to which groupwill element 117 belong? Explain your answer.
7. Applying Concepts Are the properties ofsodium, Na, more like the properties of lithium,Li, or magnesium, Mg? Explain your answer.
Interpreting Graphics
8. The image below shows part of a periodic table.Compare the image below with the similar partof the periodic table in your book.
Topic: Periodic Table; MetalsSciLinks code: HSM1125; HSM0947
• Mendeleev developed the first periodictable by listing the elements in order ofincreasing atomic mass. He used his tableto predict that elements with certain prop-erties would be discovered later.
• Properties of elements repeat in a regular,or periodic, pattern.
• Moseley rearranged the elements in orderof increasing atomic number.
• The periodic law states that the repeat-ing chemical and physical propertiesof elements relate to and depend onelements’ atomic numbers.
• Elements in the peri-odic table are classifiedas metals, nonmetals, andmetalloids.
• Each element has a chemical symbol.
• A horizontal row of elements is called aperiod.
• Physical and chemical properties ofelements change across each period.
• A vertical column of elements is called agroup or family.
• Elements in a group usually have similarproperties.
AlternativeAssessment ---------------------------g
Element Report Photocopythe periodic table, and cut thesquares of the elements out ofthe copy. Fold each square inhalf, and put the squares into abox. Ask each student to selectthree squares and then write ashort report for each element.The report should include
• the full chemical name ofeach element
• identification of each elementas a metal, a metalloid, or anonmetal
• the order of the three elementsby increasing atomic mass
• identification of each element’sgroup and period
• any interesting facts aboutor important uses of eachelementl Logical
Answers to Section Review
1. Sample answer: Periodicmeans “happening in a regularrepeating pattern.”
2. c3. A period in the periodic
table is a horizontal row ofel ements. A group is a verticalcolumn of elements.
4. atomic mass5. The repeating chemical
and physical properties ofelements change periodicallywith the atomic numbers ofthe elements.
6. Group 17; Element 117 has117 protons. So, it would fallunder astatine in the periodictable.
7. lithium; Sodium and lithiumare in the same group, so theirproperties should be more alikethan the properties of sodiumand magnesium are.
8. The periodic table has thesame shape, atomic numbers,and chemical symbols. Thenames of the elements are in adifferent language (Japanese).
CHAPTER RESOURCES
Chapter Resource File
• Section Quizg• Section Reviewg• Vocabulary and Section Summaryg• SciLinks Activityg• Datasheet for Quick Lab
CRF
Section 1 • Arranging the Elements 343
READING STRATEGY
Grouping the ElementsYou probably know a family with several members who look a lot alike. The elements in a family or group in the periodic table often—but not always—have similar properties.
The properties of the elements in a group are similar becausethe atoms of the elements have the same number of electronsin their outer energy level. Atoms will often take, give, or shareelectrons with other atoms in order to have a complete set ofelectrons in their outer energy level. Elements whose atomsundergo such processes are called reactive and can combine toform compounds.
Group 1: Alkali Metals
Alkali metalsAlkali metals (AL kuh LIE MET uhlz) are elements inGroup 1 of the periodic table. They share physicaland chemical properties, as shown in Figure 1. Alkalimetals are the most reactive metals because their atomscan easily give away the one outer-level electron. Purealkali metals are often stored in oil. The oil keeps themfrom reacting with water and oxygen in the air. Alkalimetals are so reactive that in nature they are foundonly combined with other elements. Compoundsformed from alkali metals have many uses. For exam-ple, sodium chloride (table salt) is used to flavor yourfood. Potassium bromide is used in photography.
2
Group contains: metalsElectrons in the outer level: 1Reactivity: very reactiveOther shared properties: softness; color of silver;shininess; low density
Alkali metals react with water to form hydrogen gas.
Sodium Sodium Potassium
Alkali metals are soft enough to be cut with a knife.
Properties of Alkali MetalsFigure 1
What You Will Learn
Explain why elements in a groupoften have similar properties.Describe the properties of theel ements in the groups of theperiodic table.
Vocabularyalkali metalalkaline-earth metalhalogennoble gas
Paired Summarizing Read thissection silently. In pairs, take turnssummarizing the material. Stop to dis-cuss ideas that seem confusing.
Lithium
3Li
Sodium
11Na
Potassium
19K
Rubidium
37Rb
Cesium
55Cs
Francium
87Fr
Although the element hydro-gen appears
above the alkali metals on the periodic table, it is not considered a mem-ber of Group 1. It will be described separately at the end of this section.
OverviewStudents learn how properties ofelements are used to group theelements in the periodic table.Students also study the relation-ship that elements have to eachother and to the overall layoutof elements within the table.
BellringerAsk students the following ques-tions: “How do you know thata bird is a bird, that a kangaroois a kangaroo, and that a shark isa shark?” “What characteristicsof each animal help you to tellthe animals apart?” and “Howcan such an analysis of charac-teristics be applied to elements?”
Discussion ----------------------------------g
Universal Ingredients Handout several kinds of cookies. Askstudents to list the ingredients.(The goal is to list all of thethings from which you canmake cookies.) Show studentsthe list of ingredients for theentire universe—the periodictable of the elements. Discusswith students how theseelements combine to make allmatter. You can also remind stu-dents that the basic ingredientsof the atoms of the elementsare protons, neutrons, and electrons. l Visual
2
MISCONCEPTIONALERT
Explosive Alkali Metals? Textbooksoften show photos of an alkali metalreacting explosively with water and pro-ducing flames. Students should be awarethat the metal itself is not burning.When the metal reacts with water, oneof the products is hydrogen gas. Theenergy released during the reactionoften ignites the flammable hydrogen,thus producing flames. Also, the reactiv-ity of alkali metals with water varies.
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344 Chapter 12 • The Periodic Table
VSc
Y
Ti
Zr Nb
Cr
Mo
Mn Fe
Ru
Co
RhTc Pd Ag Cd
Ni Cu Zn
La
Ac
H f
Rf
Ta
Db
W
Sg
Re
Bh
IrOs
Hs Mt
Pt
Ds Uuu
Au Hg
Uub
21
39
57
89
22
40
72
104
23
41
73
105
24
42
74
106
25
43
75
107
26
44
76 77
108
27
45
109
28 29 30
46 47 48
78 79 80
110 111 112
Alkaline-earth metals (AL kuh LIEN UHRTH MET uhlz) areless reactive than alkali metals are. Atoms of alkaline-earthmetals have two outer-level electrons. It is more difficult foratoms to give two electrons than to give one when joiningwith other atoms. Group 2 elements and their compoundshave many uses. For example, magnesium can be mixedwith other metals to make low-density materials used inairplanes. And compounds of calcium are found in cement,chalk, and even you, as shown in Figure 2.
alkali metal one of theelements of Group 1 ofthe periodic table (lithium,sodium, potassium, rubid-ium, cesium, and francium)
alkaline-earth metal oneof the elements of Group 2of the periodic table (beryl-lium, magnesium, calcium,strontium, barium, andradium)
Figure 2 Calcium, analkaline-earth metal, isan important part of acompound that keepsyour bones and teethhealthy.
Group contains: metalsElectrons in the outer level: 1 or 2Reactivity: less reactive than alkaline-earth metalsOther shared properties: shininess; good conductors of thermal energyand electric current; higher densities and melting points than elements inGroups 1 and 2 (except for mercury)
Group contains: metalsElectrons in the outer level: 2Reactivity: very reactive but less reactive than alkali metalsOther shared properties: color of silver; higher densities thanalkali metals
Groups 3–12 do not have individual names. Instead, all of thesegroups are called transition metals. The atoms of transition metalsdo not give away their electrons as easily as atoms of the Group 1and Group 2 metals do. So, transition metals are less reactive thanalkali metals and alkaline-earth metals are.
✓Reading Check Why are alkali metals more reactive than transitionmetals are? (See the Appendix for answers to Reading Checks.)
Group 2: Alkaline-Earth Metals
Groups 3–12: Transition Metals
BerylliumBe
4
MagnesiumMg
12
CalciumCa20
StrontiumSr38
BariumBa56
RadiumRa
88
Answer to Reading Check
It is easier for atoms of alkali metals to losetheir outer electron than for atoms of transitionmetals to lose their outer electrons. Therefore,alkali metals are more reactive than transitionmetals.
StrategiesStrategiesINCLUSIONINCLUSION
• Gifted and TalentedSome students benefit from studying atopic in greater depth. Assign each ofthese students one of the groups fromthe periodic table. Ask students toresearch the elements in the group andto make a poster showing some uses forthose elements. l Visual/Logical
CulturalAwarenessCulturalAwareness g
From the Arabic The alkalimetals in Group 1, whichinclude potassium, got theirgroup name from Arabic.Hundreds of years ago, toisolate potassium compoundsfrom plant matter, peopleburned plants, dissolved theashes in water, and boiled offthe water in large pots. Thepowdery residue left behind,potassium carbonate, wascalled potash. The Arabicword for potash is al-qili.l Verbal
SUPPORT FOR
English LanguageLearnersElement Groups To help stu-dents become more familiarwith the various propertiesof the element groups, havepairs of students write thenames of each group on sepa-rate index cards. Ask studentsto place the groups in orderbased on various criteria (re-activity, number of elements,density, and so on). After youname each criteria, give thepairs time to order their cards,and, then, review the properorder and the reason for it asa class before moving to thenext criteria. Encourage stu-dents to ask questions abouteach order.l Verbal/Logical
Section 2 • Grouping the Elements 345
Lanthanum
57
Actinium
89
Lanthanides
Actinides
58 59 60 61 62 63 64 65 66 67 68 69 70 71
90 91 92 93 94 95 96 97 98 99 100 101 102 103
La
Ac
Ce
Th
Pr
Pa
Nd
U
Pm
Np
Sm
Pu
Eu
Am
Gd
Cm
Tb
Bk
Dy
Cf
Ho
Es
Er
Fm
Tm
Md
Yb
No
Lu
Lr
Properties of Transition MetalsThe properties of the transition metals vary widely, as shown in Figure 3. But, because these elements are metals, they share the properties of metals. Transition metals tend to be shiny and to conduct thermal energy and electric current well.
Lanthanides and ActinidesSome transition metals from Periods 6 and 7 appear in two rows at the bottom of the periodic table to keep the table from being too wide. The elements in each row tend to have similar properties. Elements in the first row follow lanthanum and are called lanthanides. The lanthanides are shiny, reactive metals. Some of these elements are used to make steel. An important use of a compound of one lanthanide element is shown in Figure 4.
Elements in the second row follow actinium and are calledactinides. All atoms of actinides are radioactive, or unstable. The atoms of a radioactive element can change into atoms of another element. Elements listed after plutonium, element 94, do not occur in nature. They are made in laboratories. Very small amounts of americ ium (AM uhr ISH ee uhm), element 95, are used in some smoke detectors.
✓Reading Check Are lanthanides and actinides transition metals?
Figure 4 Do you see red? The color red appears on a computer monitor because of a compound formed from europium that coats the back of the screen.
Mercury is used in thermometers. Unlike
the other transition metals, mercury is liquid at room temperature.
Many transition metals—but not all—are silver colored! This gold ring proves it!
Some transition metals, such as titanium in the artificial hip at right, are not very reactive. But others, such as iron, are reactive. The iron in the steel trowel on the left has reacted to form rust.
346 Chapter 12 • The Periodic Table
Titanium Titanium is a very light but very strong metal. Because of these properties, it is often used in structures such as airframes and jet engines. Titanium is highly resistant to corrosion and so can be used in very corrosive places, such as in salt water or in the human body.
Answer to Reading Check
Yes, lanthanides and actinides are transition metals.
MISCONCEPTIONALERT
Rare-Earth Elements On older periodic tables, the lan-thanides may be called the rare-earth elements, although this name is incorrect. Many of the lanthanides are more abundant than elements that are more well known are. The lanthanides are also often referred to as a series.Remind students that these elements (and the actinides) belong in the periodic table where their atomic numbers fit. However, the periodic table would be too wide to print or work with easily if these elements were printed in their proper place.
Is That a Fact!Mercury in Thermometers Mercury has been the liquid of choice for use in thermometers because as temperature changes, mercury expands and contracts at a nearly constant rate. That is, for every 1° change in temperature, mercury’s volume changes consistently.
In a meeting of the transition metals, mercury wished to speak to the entire group. But the group didn’t let mercury speak because they didn’t like to listen to heavy metal.
Group 13: Boron Group
The most common element from Group 13 is alumi-num. In fact, aluminum is the most abundant metalin Earth’s crust. Until the 1880s, however, aluminumwas considered a precious metal because the processused to make pure aluminum was very expensive.During the 1850s and 1860s, Emperor Napoleon III ofFrance used aluminum dinnerware because aluminumwas more valuable than gold.
Today, the process of making pure aluminum iseasier and less expensive than it was in the 1800s.Aluminum is now an important metal used in mak-ing aircraft parts. Aluminum is also used to makelightweight automobile parts, foil, cans, and siding.
Like the other elements in the boron group, alu-minum is reactive. Why can it be used in so manythings? A thin layer of aluminum oxide quickly formson aluminum’s surface when aluminum reacts withoxygen in the air. This layer prevents further reactionof the aluminum.
Group contains: one metalloid and five metalsElectrons in the outer level: 3Reactivity: reactiveOther shared properties: solids at room temperature
Figure 5 Diamond and soot have very different properties, yet both are natural forms of carbon.
Group 14: Carbon Group
The nonmetal carbon can be found uncombined innature, as shown in Figure 5. Carbon also forms a widevariety of compounds. Some of these compounds,such as proteins, fats, and carbohydrates, are neces-sary for living things on Earth.
The metalloids silicon and germanium, also inGroup 14, are used to make computer chips. Themetal tin is useful because it is not very reactive. Forexample, a tin can is really made of steel coated withtin. Because the tin is less reactive than the steel is,the tin keeps the iron in the steel from rusting.
✓✓Reading Check What metalloids from Group 14 are used to make computer chips?
RecyclingAluminum
Aluminum recycling is a very successful program. In your science journal, write a one-page report that describes how aluminum is processed from its ore. In your report, identify the ore and compare the energy needed to extract aluminum from the ore with the energy needed to process recycled aluminum.
WRITINGSKILL
Group contains: one nonmetal, two metalloids, and three metalsElectrons in the outer level: 4Reactivity: varies among the elementsOther shared properties: solids at room temperature
Indium
49In
Thallium
81Tl
Ununtrium
113Uut
Gallium
31Ga
Aluminum
13Al
Boron
5B
Tin
50Sn
Lead
82Pb
Ununquadium
114Uuq
Germanium
32Ge
Silicon
14Si
Carbon
6C
Diamond is the hardest ma terialknown. It is used as a jewel and on cutting tools, such as saws, drills, and files.
Soot is formed from burning oil, coal, and wood and is used as a pigment in paints and crayons.
CONNECTIONCONNECTION vvMath ---------------------------------------------------------------------------g
Relative Masses The atomicmasses of helium and carbon areapproximately 4 and 12, respec-tively. Ask students the follow-ing questions: “How manyhelium atoms would togetherhave about the same mass asone carbon atom? How manyhelium atoms would togetherhave the mass of one siliconatom?” (Three helium atomstogether have the same mass asone carbon atom, and seven heliumatoms together have the same massas one silicon atom.) l Logical
CONNECTION toCONNECTION toHistory --------------------------------------------------g
Canning Food preservationthrough canning was inventedin 1809 by Frenchman Nicolas-François Appert (c. 1750–1841).Tin-plated cans were first usedfor canning in 1810 by Englishinventor Peter Durand. Com-mercial canning was brought tothe United States in 1821 whenit was introduced by the WilliamUnderwood Company in Boston.In 1874, the canning process wasgreatly improved when cans werefirst heated by high-pressuresteam. The high pressure in thisprocess kept cans from burstingduring heating.
Using the Figure ----g
Allotropes Many elements haveseveral forms, called allotropes. Forexample, oxygen gas and ozoneare allotropes of oxygen. Allo-tropes are usually stable at differ-ent temperatures and pressures.For example, diamond, graphite,and buckyballs are allotropes ofcarbon. Refer to Figure 5.l Visual
Answer to Reading Check
silicon and germanium
CHAPTER RESOURCESWorkbooks
Math Skills for Science• Checking Division with Multiplicationg
Is That a Fact!Less than 50 years ago, most scientistsbelieved that silicon had little commer-cial use. They didn’t foresee the inven-tion of the silicon transistor chip, whichled the way for the development ofcomputer chips. Now, industrial proc-esses using silicon employ millions ofpeople worldwide. The main siliconproduct, integrated circuits for com-puter and game chips, has changedthe world.
Section 2 • Grouping the Elements 347
Group 15: Nitrogen Group
Nitrogen, which is a gas at room temperature, makesup about 80% of the air you breathe. Nitrogenremoved from air can be reacted with hydrogen tomake ammonia for fertilizers.
Although nitrogen is not very reactive, phosphorusis extremely reactive, as shown in Figure 6. In fact,in nature phosphorus is only found combined withother elements.
Figure 6 Simply striking a match on the side of this box causes chemicals on the match to react with phosphorus on the box and begin to burn.
Figure 7 This diver is breathing a mix-ture that contains oxygen gas.
Group contains: two nonmetals, two metalloids, and two metalsElectrons in the outer level: 5Reactivity: varies among the elementsOther shared properties: solids at room temperature (except for nitrogen)
Group 16: Oxygen Group
Oxygen makes up about 20% of air. Oxygen is neces-sary for substances to burn. Oxygen is also importantto most living things, such as the diver in Figure 7. Sul-fur is another commonly found member of Group 16.Sulfur can be found as a yellow solid in nature. Itis used to make sulfuric acid, the most widely usedcompound in the chemical industry.
✓✓Reading Check Which gases from Groups 15 and 16 make up most of the air you breathe?
Group contains: three nonmetals, one metalloid, and one metalElectrons in the outer level: 6Reactivity: ReactiveOther shared properties: All but oxygen are solid at room temperature.
For another activity related to this chapter, go to go.hrw.com and type in the keyword HP5PRTW.
ArsenicAs33
PhosphorusP15
NitrogenN7
AntimonySb51
BismuthBi83
UnunpentiumUup
115
SeleniumSe34
SulfurS16
OxygenO8
TelluriumTe52
PoloniumPo84
Research -------------------------------------------g
PORTFOLIO
Sulfuric Acid Ask stu-dents to find out more
about sulfur and sulfuric acid.Sulfuric acid is widely used inthe chemical industry. Havestudents find out how and whyit is so widely used. Studentsmay also investigate sulfur, sul-furic acid, smog, and acid rain.l Verbal/Logical
CONNECTIONCONNECTION vvHistory --------------------------------------------------a
Writing Sulfur Sulfur was usedby prehistoric people as apigment for cave draw-
ings. It was also used in Egyptianceremonies 4,000 years ago andin Chinese fireworks in about500 BCE. Sulfur is even men-tioned in Greek mythology. Havestudents write a report, make aposter, or prepare a presentationon the ways that sulfur was usedbefore it was recognized as an element in 1777.l Verbal ee
Answer to Reading Check
nitrogen and oxygen
CHAPTER RESOURCESWorkbooks
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348 Chapter 12 • The Periodic Table
Group 17: Halogens
Halogens (HAL oh juhnz) are very reactive nonmetals because their atoms need to gain only one electron to have a complete outer level. The atoms of halogens combine readily with other atoms, especially met-als, to gain that missing electron. The reaction of a halogen with a metal makes a salt, such as sodium chloride. Both chlorine and iodine are used as disin-fectants. Chlorine is used to treat water. Iodine mixed with alcohol is used in hospitals.
Although the chemical properties of the halogens are similar, the physical properties are quite different, as shown in Figure 8.
halogen one of the elements of Group 17 of the periodic table (fluorine, chlorine, bromine, iodine, and astatine); halogens combine with most metals to form salts
Group contains: nonmetalsElectrons in the outer level: 7Reactivity: very reactiveOther shared properties: poor conductors of electric current; violent reactions with alkali metals to form salts; never in uncombined form in nature
Physical Properties of Some HalogensFigure 8
Water Treatment Chlorine has been used to treat drinking water since the early 20th century. Chlorinating water helps protect people from many diseases by killing the organisms in water that cause the diseases. But there is much more to water treatment than just adding chlorine. Research how a water treatment plant purifies water for your use. Construct a model of a treatment plant. Use labels to describe the role of each part of the plant in treating the water you use each day.
BromineBr35
ChlorineCl17
FluorineF9
IodineI53
AstatineAt85
Chlorine is a yellowish green gas.
Bromine is a dark red liquid.
Iodine is a dark gray solid.
Section 2 • Grouping the Elements 349
CulturalAwarenessCulturalAwareness g
The Curies About a century ago, Marie Sklodowska Curie (1867–1934) made many contributions to the study of radioactivity and radio-active elements. In 1903, Marie, her husband, Pierre Curie (1859–1906), and French physicist Henri Becquerel (1852–1908) were awarded the Nobel Prize in physics for their contribu-tions to understanding radioactivity. The Curies dis-covered the radioactive ele-ments polonium and radium and isolated samples of these elements from tons of ore. For her discoveries of polo-nium and radium, Marie Curie was awarded the Nobel Prize in chemistry in 1911.
CONNECTION toCONNECTION toAstronomy -------------------------------------------g
Element Factories Stars seem to be the factories that make the naturally occurring elements throughout the universe. Students can find information about and photographs of areas in the uni-verse where new stars are born and areas where old stars have exploded. Have students research how elements may be generated or changed in these violent reactions. l Logical
h-----------------------------a
Salt Formers The word halogen comes from the Greek words meaning “salt for-mer.” Sodium chloride, or table salt, is composed of the halogen chlorine and the alkali metal sodium. Have students research halogens and their uses and then prepare a chart or a poster that shows what the stu-dents learned. l Visual/Logical
Group 18: Noble Gases
Noble gases are unreactive nonmetals and are in Group 18 of the periodic table. The atoms of these elements have a full set of electrons in their outer level. So, they do not need to lose or gain any electrons. Under normal conditions, they do not react with other elements. Earth’s atmosphere is almost 1% argon. But all the noble gases are found in small amounts.
The unreactivity of the noble gases makes them useful. For example, ordinary light bulbs last longer when they are filled with argon. Because argon is unreactive, it does not react with the metal filament in the light bulb even when the filament gets hot. A more reactive gas might react with the filament, caus-ing the light to burn out. The low density of helium makes blimps and weather balloons float. Another popular use of noble gases is shown in Figure 9.
Why are noble gases unreactive?
Hydrogen
The properties of hydrogen do not match the prop-erties of any single group, so hydrogen is set apart from the other ele ments in the table. Hydrogen is above Group 1 because atoms of the alkali metals also have only one electron in their outer level. Atoms of hydrogen can give away one electron when they join with other atoms. However, the physical properties of hydrogen are more like those of nonmetals than those of metals. So, hydrogen really is in a group of its own. Hydrogen is found in stars. In fact, it is the most abundant element in the universe. Its reactive nature makes it useful as a fuel in rockets, as shown in Figure 10.
noble gas one of the elements of Group 18 of the periodic table (helium, neon, argon, krypton, xenon, and radon); noble gases are unreactive
Figure 10 Hydrogen reacts violently with oxygen. The hot water vapor that forms as a result of this reaction helps guide the space shuttle into orbit.
Figure 9 In addition to neon, other noble gases can be used to make “neon” lights.
Group contains: nonmetalsElectrons in the outer level: 8 (except helium, which has 2)Reactivity: unreactiveOther shared properties: colorless, odorless gases at room temperature
Electrons in the outer level: 1Reactivity: reactiveOther properties: colorless, odorless gas at room tem-perature; low density; explosive reactions with oxygen
✓Reading Check
KryptonKr36
ArgonAr18
NeonNe10
HeliumHe
2
XenonXe54
RadonRn
86
HydrogenH1
350 Chapter 12 • The Periodic Table
Reteaching---------------------------------------b
Mendeleev, May I? To help students remember the proper-ties of the groups, use chalk to draw a giant periodic table on the ground. Divide students into groups and play a game of Mother, may I? Give each group a command such as “Go to the group whose elements are unreactive.” Students must decide where on the periodic table they should go and must ask you “Mendeleev, may we go to Group 18?” If they are correct, they should move to that area of the periodic table. l Kinesthetic/Interpersonal
Quiz ---------------------------------------------------------------------g
1. Using the periodic table, determine which two groups include highly reactive metals. (on the left, Groups 1 and 2)
2. What are the actinides? What is one characteristic of all actinides? (the elements that follow actinium and that have atomic numbers 90–103; All actinides are radioactive.)
3. Of the gases oxygen, argon, chlorine, and neon, which two would be the most chem-ically reactive? (Oxygen and chlorine would be. Argon and neon are in Group 18, which con-sists of the noble gases, which are very unreactive.)
Answer to Reading Check
Atoms of noble gases have a full set of electrons in their outer level. MISCONCEPTION
ALERT
Inert Gases Noble gases were originally called inert gases becauseit was thought that they would not react with any elements. However, scientists are able to use high tempera-tures and pressures to cause some of the elements in Group 18 to react. Thus, the term inert is incorrect, and the term noble is preferred.
For a variety of links related to thischapter, go to www.scilinks.org
SummarySummary
Review
• Alkali metals (Group 1) are the mostreactive metals. Atoms of the alkalimetals have one electron in theirouter level.
• Alkaline-earth metals (Group 2) are lessreactive than the alkali metals are. Atomsof the alkaline-earth metals have twoelectrons in their outer level.
• Transition metals (Groups 3–12) includemost of the well-known metals and thelanthanides and actinides.
• Groups 13–16 contain the metalloidsand some metals and nonmetals.
• Halogens (Group 17) are very reactive non-metals. Atoms of the halogens have sevenelectrons in their outer level.
• Noble gases (Group 18) are unreactivenonmetals. Atoms of the noble gases havea full set of electrons in their outer level.
• Hydrogen is set off by itself in the periodictable. Its properties do not match theproperties of any one group.
Using Key Terms
Complete each of the following sentences bychoosing the correct term from the word bank.
noble gas alkaline-earth metalhalogen alkali metal
1. An atom of a(n) has a full set of electrons inits outermost energy level.
2. An atom of a(n) has one electron in itsoutermost energy level.
3. An atom of a(n) tends to gain one electronwhen it combines with another atom.
4. An atom of a(n) tends to lose two electronswhen it combines with another atom.
Understanding Key Ideas
5. Which group contains elements whose atomshave six electrons in their outer level?
a. Group 2 c. Group 16b. Group 6 d. Group 18
6. What are two properties of the alkali metals?
7. What causes the properties of elements in agroup to be similar?
8. What are two properties of the halogens?
9. Why is hydrogen set apart from the otherelements in the periodic table?
10. Which group contains elements whose atomshave three electrons in their outer level?
Interpreting Graphics
11. Look at the model of an atom below. Does themodel represent a metal atom or a nonmetalatom? Explain your answer.
Critical Thinking
12. Making Inferences Why are neither the alkalimetals nor the alkaline-earth metals founduncombined in nature?
13. Making Comparisons Compare the elementhydrogen with the alkali metal sodium.
Topic: Alkali Metals; Halogens andNoble Gases
SciLinks code: HSM0043; HSM0711
AlternativeAssessment ---------------------------g
Concept Mapping Have stu-dents prepare a concept map ofthe Periodic Table of the Elements,showing the groups as discussedin this chapter and the charac-teristics of each group or set ofgroups. Students do not have toshow each individual element oreach separate group. l Visual
Answers to Section Review
1. noble gas2. alkali metal3. halogen4. alkaline-earth metal5. c6. Answers may vary but
could include that alkali metalshave one electron in their outerlevel; are very reactive; aresoft, silver colored, and shiny;and have a low density.
7. having the same number ofelectrons in the outer level oftheir atoms
8. Answers may vary butcould include that halogenshave seven electrons in theirouter level, are very reactive,conduct electric current poorly,react violently with alkali met-als to form salts, and are neverfound uncombined in nature.
9. The properties of hydrogendo not match the propertiesof any single group.
10. boron group (Group 13)11. metal; The model shows two
electrons in the outer level, sothe atom represented is mostlikely a metal.
12. They are so reactive that theyreact with water or oxygen inthe air.
13. Both hydrogen and sodiumhave one electron in their outerlevel. Atoms of both elementsgive away one electron whenjoining with other atoms. Buthydrogen is a nonmetal andis a gas at room temperature,whereas sodium is a metal andis a solid at room temperature.
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Section 2 • Grouping the Elements 351
Model-Making Lab
Create a Periodic TableYou probably have classification systems for many things inyour life, such as your clothes, your books, and your CDs. Oneof the most important classification systems in science is theperiodic table of the elements. In this lab, you will developyour own classification system for a collection of ordinaryobjects. You will analyze trends in your system and compareyour system with the periodic table of the elements.
Procedure
1 Your teacher will give you a bag of objects. Your bag is missingone item. Examine the items carefully. Describe the missingobject in as many ways as you can. Be sure to include thereasons why you think the missing object has the charac-teristics you describe.
2 Lay the paper squares out on your desk or table so that youhave a grid of five rows of four squares each.
3 Arrange your objects on the grid in a logical order. (You mustdecide what order is logical!) You should end up with oneblank square for the missing object.
4 Record a description of the basis for your arrangement.
Classify objects based ontheir properties.
Identify patterns and trendsin data.
• bag of objects
• balance, metric
• meterstick
• paper, graphing (2 sheets)
• paper, 3 � 3 cm squares (20)
OBJECTIVES
MATERIALS
Model-MakingModel-Making LabLab
Create a Periodic Table
Teacher’s Notes
Time RequiredOne to two 45-minute classperiods
Lab Ratings
rTeacher Prep fff
Student Set-Up f
Concept Level fff
Clean Up f
M A T E R I A L SFor each group of 2–4 students,assemble a collection of 20 objects(5 sets of 4 objects). You should pro-vide a bag containing 19 of theseobjects. A recommended collectionof objects includes sets of coins(pennies, nickels, dimes, and quar-ters), sets of buttons that are similarbut vary in diameter, and washersthat vary in diameter. Other objects,such as nuts, bolts, and paper cir-cles, will work and may be obtainedeasily. The difference in massesshould be large enough for a beambalance to detect. Ideally, each set(one column on the table) should beof the same material and thicknessand vary only in diameter.
Preparation NoteYou may have students preparethe 20 squares of paper, but thelab will go faster if the squaresare prepared ahead of time.
CHAPTER RESOURCES
Chapter Resource File
CRF • Datasheet for Chapter Lab• Lab Notes and Answers
Technology
Classroom Videos• Lab Video
Norman Holcomb
Marion Elementary SchoolMaria Stein, Ohio
Holt Lab Generator CD-ROMSearch for any lab by topic, standard, difficulty level,or time. Edit any lab to fit your needs, or create yourown labs. Use the Lab Materials QuickList softwareto customize your lab materials list.
CLASSROOM
TESTED& APPRO
VED
352 Chapter 12 • The Periodic Table
5 Measure the mass (g) and diameter (mm) of each object, and record your results in the appropriate square. Each square (except the empty one) should have one object and two written measurements on it.
6 Examine your pattern again. Does the order in which your objects are arranged still make sense? Explain.
7 Rearrange the squares and their objects if necessary to improve your arrangement. Record a description of the basis for the new arrangement.
8 Working across the rows, number the squares 1 to 20. When you get to the end of a row, continue numbering in the first square of the next row.
9 Copy your grid. In each square, be sure to list the type of object and label all measurements with appropriate units.
Analyze the Results
1 Constructing Graphs Make a graph of mass (y-axis) versus object number (x-axis). Label each axis, and title the graph.
2 Constructing Graphs Now make a graph of diameter ( y-axis) versus object number (x-axis).
Draw Conclusions
3 Analyzing Graphs Discuss each graph with your classmates. Try to identify any important features of the graph. For example, does the graph form a line or a curve? Is there anything unusual about the graph? What do these features tell you? Record your answers.
4 Evaluating Models How is your arrange-ment of objects similar to the periodic table of the elements found in this textbook? How is your arrangement different from that periodic table?
5 Making Predictions Look again at your pre-diction about the missing object. Do you think your prediction is still accurate? Try to improve your description by estimating the mass and diameter of the missing object. Record your estimates.
6 Evaluating Methods Mendeleev created a periodic table of elements and predicted characteristics of missing elements. How is your experiment similar to Mendeleev’s work?
Chapter 12 • Chapter Lab 353
Analyze the Results
1. Graphs should be similar to sample graph A.
2. Graphs should be similar to sample graph B.
Draw Conclusions
3. Answers may vary. The primary feature is the repeating pattern of increases. This pattern in the first graph indicates the peri-odic nature of the mass of the items. This pattern in the sec-ond graph indicates the peri-odic nature of the diameter of the items.
4. Answers may vary. Similarities include repeating patterns (such as patterns of increasing mass) across the table. Differences may include no consistent family traits and no chemical properties associated with position in the table.
5. Answers may vary depending on the student’s original predic-tion. Accept all reasonable answers. (You may wish to provide the students with the missing object so that they can further evaluate their prediction.)
6. This experiment is similar in that a pattern that helped identify characteristics of a missing object was identified.
CHAPTER RESOURCESWorkbooks
Whiz-Bang Demonstrations • Waiter, There’s Carbon in My
Sugar Bowl! b
Inquiry Labs • The Chemical Side of Light g
Long-Term Projects & Research Ideas • It’s Element-ary a
Mas
s
Object number
A
Dia
met
er
Object number
B
7 Which of the following items is NOT found on the periodic table?
a. the atomic number of each elementb. the name of each elementc. the date that each element was
discoveredd. the atomic mass of each element
8 Which of the following statements about the periodic table is false?
a. There are more metals than non-metals on the periodic table.
b. Atoms of elements in the same group have the same number of electrons in their outer level.
c. The elements at the far left of the periodic table are nonmetals.
d. Elements are arranged by increasing atomic number.
9 Which of the following statements about alkali metals is true?
a. Alkali metals are generally found in their uncombined form.
b. Alkali metals are Group 1 elements.c. Alkali metals should be stored
underwater.d. Alkali metals are unreactive.
0 Which of the following statements about elements is true?
a. Every element occurs naturally.b. All elements are found in their
uncombined form in nature.c. Each element has a unique atomic
number.d. All of the elements exist in approxi-
mately equal quantities.
Complete each of the following sen-tences by choosing the correct term from the word bank.
group periodalkali metals halogensalkaline-earth metals noble gases
1 Elements in the same vertical column on the periodic table belong to the same .
2 Elements in the same horizontal row on the periodic table belong to the same .
3 The most reactive metals are .
4 Elements that are unreactive are called .
Multiple Choice
5 Mendeleev’s periodic table was useful because it
a. showed the elements arranged by atomic number.
b. had no empty spaces.c. showed the atomic number of the
elements.d. allowed for the prediction of the
properties of missing elements.
6 Most nonmetals are
a. shiny.b. poor conductors of electric current.c. fl attened when hit with a hammer.d. solids at room temperature.
USING KEY TERMS
UNDERSTANDING KEY IDEAS
354 Chapter 12 • The Periodic Table
ANSWERS
Using Key Terms1. group2. period3. alkali metals4. noble gases
Understanding Key Ideas5. d6. b7. c8. c9. b
10. c
Assignment GuideSECTION QUESTIONS
1 1–2, 5–8, 10–12, 15–16, 19–20
2 3–4, 9, 13–14, 18
1 and 2 17
?
Short Answer
q How is Moseley’s basis for arrang-ing the elements different fromMendeleev’s?
w How is the periodic table like acalendar?
Math Skills
Examine the chart of the percentagesof elements in the Earth’s crust below.Then, answer the questions that follow.
e Excluding the “Other” category, whatpercentage of the Earth’s crust arealkali metals?
r Excluding the “Other” category, whatpercentage of the Earth’s crust arealkaline-earth metals?
tConcept Mapping Use the followingterms to create a concept map: periodictable, elements, groups, periods, metals,nonmetals, and metalloids.
yForming Hypotheses Why was Men-deleev unable to make any predictionsabout the noble gas elements?
u Identifying Relationships When anelement that has 115 protons in itsnucleus is synthesized, will it be ametal, a nonmetal, or a metalloid?Explain your answer.
iApplying Concepts Your classmateoffers to give you a piece of sodiumthat he found on a hiking trip. What isyour response? Explain.
oApplying Concepts Identify eachelement described below.
a. This metal is very reactive, hasproperties similar to those of mag-nesium, and is in the same period asbromine.
b. This nonmetal is in the same groupas lead.
p Study the diagram below to determinethe pattern of the images. Predict themissing image, and draw it. Identifywhich properties are periodic andwhich properties are shared within agroup.
46.6% O
27.7% Si
2.0% Mg
2.8% Na
3.6% Ca
5.0% Fe
8.1% Al
2.6% K
1.6% Other
CRITICAL THINKING
INTERPRETING GRAPHICS
11. Moseley arranged elements byincreasing atomic number.Mendeleev arranged elementsby increasing atomic mass.
12. Both are periodic. The periodictable has repeating propertiesof elements. The calendar hasrepeating days and months.
13. 5.4% (sodium and potassium)14. 5.6% (magnesium and calcium)
Critical Thinking15. An answer to this
exercise can befound at the endof this book.
16. Mendeleev could make predic-tions only about elementswhere there were clear gaps inhis table. Because no noblegases were known at the time,there were no obvious gaps inthe table and no way that hecould have known that a wholecolumn was missing.
17. metal; it will be located belowthe metal bismuth to the left ofthe zigzag
18. I would tell my classmate thathe didn’t find sodium. Sodium isvery reactive and cannot befound uncombined in nature.Sodium would react with oxy-gen and water in the air to formcompounds.
19. a. calciumb. carbon
Interpreting Graphics20.
Periodic properties are theorder of the shapes and thenumber of lines inside theshape. The properties sharedin a group are the shape andthe color of the lines insidethe shape.
CHAPTER RESOURCES
Chapter Resource File
• Chapter Reviewg• Chapter Test Ag• Chapter Test Ba• Chapter Test Cs• Vocabulary Activityg
Workbooks
Study Guide• Study Guide is also available in Spanish.
CRF
Chapter 12 • Chapter Review 355
MISCONCEPTIONALERT
READING
READINGRead each of the passages below. Then, answer the questions that follow each passage.
Passage 1 Napoleon III (1808–1873) ruled as emperor of France from 1852 to 1870. Napoleon III was the nephew of the famous French military leader and emperor Napoleon I. Early in his reign, Napoleon III was an authoritarian ruler. France’s economy did well under his dictatorial rule, so the French rebuilt cities and built railways. During the 1850s and 1860s, Napoleon III used aluminum dinnerware because aluminum was more valuable than gold. Despite his wealth and French eco-nomic prosperity, Napoleon III lost public support and popularity. So, in 1860, he began a series of reforms that allowed more individual freedoms in France.
1. What is the meaning of the word authoritarianin the passage?
A controlling people’s thoughts and actionsB writing books and storiesC being an expert on a subjectD being very wealthy
2. Which of the following statements best describes why Napoleon III probably changed the way he ruled France?
F He was getting old.G He was unpopular and had lost public
support.H He had built as many railroads as he could.I He used aluminum dinnerware.
3. According to the passage, in what year did Napoleon III die?
A 1808B 1873C 1860D 1852
Passage 2 Named after architect Buckminster Fuller, buckyballs resemble the geodesic domes that are characteristic of the architect’s work. Excitement over buckyballs began in 1985, when scientists projected light from a laser onto a piece of graphite. In the soot that remained, researchers found a completely new kind of molecule! Buckyballs are also found in the soot from a candle flame. Some scientists claim to have detected buckyballs in space. In fact, one suggestion is that buckyballs are at the center of the condensing clouds of gas, dust, and debris that form galaxies.
1. Which of the following statements correctly describes buckyballs?
A They are a kind of dome-shaped building.B They are shot from lasers.C They were unknown before 1985.D They are named for the scientist who
discovered them.
2. Based on the passage, which of the following statements is an opinion?
F Buckyballs might be in the clouds that form galaxies.
G Buckyballs are named after an architect.H Scientists found buckyballs in soot.I Buckyballs are a kind of molecule.
3. According to the passage, why were scientists excited?
A Buckyballs were found in space.B An architect created a building that
resembled a molecule.C Buckyballs were found to be in condensing
clouds of gas that form galaxies.D A new kind of molecule was found.
Passage 11. A2. G3. B
Question 1: Some students may think that the word authoritarianderives from either the word author(a writer of books and stories) or the word authority (an expert on a sub-ject) because these words appear closely related. However, the correct meaning can be determined by notic-ing that the passage contrasts the early rule of Napoleon III with his later rule, in which he granted more individ-ual freedoms.
Passage 21. C2. F3. D
Question 1: The passage states that the excite-ment over buckyballs began when they were dis-covered in 1985. Buckyballs are not dome-shaped buildings; they only resemble the buildings. Shooting lasers at graphite can make buckyballs, but the buckyballs themselves are not shot from the laser. The person for whom the buckyballs are named, Buckminster Fuller, did not discover them. Fuller was an architect who was known for design-ing buildings that used geodesic domes, which happen to resemble buckyballs.
356 Chapter 12 • The Periodic Table
Teacher’s NoteTeacher’s NoteTo provide practice under more realistic testing conditions, give students 20 minutes to answer all of the questions in this Standardized Test Preparation.
Answers to the standardized test preparation can help you identify student misconcep-tions and misunderstandings.
Stand
ardized
Test Prep
aration
1. Which of the following statements is correct for the elements shown?
A Lithium has the greatest atomic number.B Sodium has the least atomic mass.C Atomic number decreases as you move
down the column.D Atomic mass increases as you move down
the column.
2. Which of the following statements best describes the outer electrons in atoms of the elements shown?
F The atoms of each element have 1 outer-level electron.
G Lithium atoms have 3 outer-level electrons, sodium atoms have 11, and potassium atoms have 19.
H Lithium atoms have 7 outer-level electrons, sodium atoms have 23, and potassium atoms have 39.
I The atoms of each element have 11 outer-level electrons.
3. The elements featured in the image belong to which of the following groups?
A noble gasesB alkaline-earth metalsC halogensD alkali metals
1. Elvira’s house is 7.3 km from her school. What is this distance expressed in meters?
A 0.73 mB 73 mC 730 mD 7,300 m
2. A chemical company is preparing a shipment of 10 g each of four elements. Each element must be shipped in its own container that is completely fi lled with the element. Which container will be the largest?
F the container of aluminumG the container of arsenicH the container of germaniumI the container of silicon
3. Arjay has samples of several common elements. Each element has a unique atomic mass (expressed in amu). Which of the following lists shows the atomic masses in order from least to greatest?
A 63.55, 58.69, 55.85, 58.93B 63.55, 58.93, 58.69, 55.85C 55.85, 58.69, 58.93, 63.55D 55.85, 63.55, 58.69, 58.93
6.9Lithium
3
23.0Sodium
11
39.1Potassium
19
Read each question below, and choose the best answer.
Use the image of the periodic table below to answer the questions that follow.
ElementDensity(g/cm3)
Mass(g)
Aluminum 2.702 10
Arsenic 5.727 10
Germanium 5.350 10
Silicon 2.420 10
INTERPRETING GRAPHICS MATH INTERPRETING GRAPHICS1. D2. F3. D
Question 1: The atomic mass and the atomic number of elements in a group increase as you move from top to bottom in the group. Students often have trouble decoding questions that ask for a ranking of quantity or size in a given direction. In this question, students must analyze the value of the atomic mass or the atomic number while moving in a stated direction along the group. An error in either thought process can result in choosing an incorrect answer.
MATH1. D2. I3. C
Question 2: Each container con-tains 10 g of an element. Therefore, the size of each container will be determined by the density of the el ement in the container. The element that has the highest density, arsenic, will require the smallest container. The element that has the lowest density, silicon, will require the largest container. Students who have difficulty with this item might benefit by comparing the volumes of equal masses of cotton and lead.
Chapter 12 • Standardized Test Preparation 357
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CRF • Standardized Test Preparation g
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in Action
Sciencein Action
Language ArtsImagine that you are trapped within a buckyball. Write a one-
page short story describing your experience. Describe the windows in your molecular prison.
WRITINGSKILL
MathFireworks can cost between $200 and $2,000 each. If a show uses 20 fireworks that cost $200 each, 12 fireworks that cost $500 each, and 10 fireworks that cost $1,200 each, what is the total cost for the fireworks?
Weird ScienceBuckyballsIn 1985, scientists found a completely new kind of molecule! This carbon molecule has 60 carbon atoms linked together in a shape similar to that of a soccer ball. This molecule is called a buckyball. Buckyballs have also been found in the soot from candle flames. And some scientists claim to have detected buckyballs in space. Chemists have been trying to identify the molecules’ properties. One property is that a buckyball can act like a cage and hold smaller substances, such as individual atoms. Buckyballs are both slip-pery and strong. Scientists are exploring their use in tough plastics and cutting tools.
Science, Technology,
and SocietyThe Science of FireworksExplosive and dazzling, a fireworks display is both a science and an art. More than 1,000 years ago, the Chinese made black powder, or gunpowder. The powder was used to set off firecrackers and primitive missiles. The shells of fireworks contain several different chemicals. Black powder at the bottom of the shell launches the shell into the sky. A second layer of black powder ignites the rest of the chemicals and causes an explosion that lights up the sky! Colors can be created by mixing chemicals such as strontium (for red), magnesium (for white), or copper (for blue) with the gunpowder.
Weird Science
BackgroundThe hexagons and pentagons of Buckminster Fuller’s geodesic domes provide great stability because they distribute stress evenly. The buckyball, C60, is one member of a large family of carbon “cages” called fullerenes.Fullerenes that have fewer than 60 carbon atoms are called buckybabies. Buckytubes have more than 60 carbon atoms and are shaped like cylinders of spiraling honeycombs.
Scientists know that high tem-peratures are needed to form buckyballs, so they look for buckyballs in intensely heated sites, such as asteroid craters and lightning strikes. Buckyball mol-ecules are found in greatest abundance in soot.
Science, Technology,
and Society
BackgroundThe colors in a fireworks display depend on the wavelengths of the light emitted by different chemicals. Light that has the shortest wavelength appears vio-let in color. Light that has the longest wavelength appears red. Refer to the chart at the bottom of the page for the colors pro-duced by various elements. Charcoal gives the fireworks a sparkling, flaming tail. Element Color
Sodium yellow
Barium green
Copper blue
Strontium red
Lithium bright red
Calcium dark red
Magnesium white
Answer to Language Arts Activity
The shapes of the windows are pentagons and hexagons. Each pentagon is surrounded by five hexagons.
Answer to Math Activity
Students should be aware that a fireworks display is costly. The cost of the display is (20 � $200) � (12 � $500) � (10 � $1200) �$22,000.
358 Chapter 12 • The Periodic Table
Write a newspaper editorial to express
an opinion for or against the Manhattan Project. Be sure to include information to support your view.
WRITINGSKILL
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articles related to this chapter by visiting go.hrw.com. Just type in the keyword HP5CS12.
Glenn T. SeaborgMaking Elements When you look at the periodic table, you can thank Dr. Glenn Theodore Seaborg and his colleagues for many of the actinide elements. While work-ing at the University of California at Berkeley, Seaborg and his team added a number of elements to the periodic table. His work in identifying properties of plutonium led to his working on the top-secret Manhattan Project at the University of Chicago. He was outspoken about the beneficial uses of atomic energy and, at the same time, opposed the production and use of nuclear weapons.
Seaborg’s revision of the layout of the periodic table—the actinide concept—is the most significant since Mendeleev’s original design. For his scientific achievements, Dr. Seaborg was awarded the 1951 Nobel Prize in Chemistry jointly with his col-league, Dr. Edwin M. McMillan. Element 106, which Seaborg neither discovered nor created, was named seaborgium in his honor. This was the first time an element had been named after a living person.
Teaching Strategy-- GENERAL
Show students that each element produces a certain color. Obtain samples of calcium chloride, strontium chloride, and sodium chloride. To prepare 0.5 M solutions, dissolve the fol-lowing quantities in separate containers with enough water to make 100 mL of each solution: 5.5 g CaCl2, 8.83 g SrCl2•H2O,and 2.9 g NaCl. Dip a different wooden splint in each solution, and use tongs to insert each splint into the flame of a porta-ble burner to burn the chemical from the splint. Try not to ignite the splints. The splints can be dipped into the solutions again if necessary.
People in Science
BackgroundSeaborg was greatly influenced by his teachers, beginning with his high school science instructor, Dwight L. Reid. When Seaborg was a graduate student at the University of California, Berkeley, his instructors included several eminent scientists, such as Gilbert N. Lewis, Axel R. Olson, William F. Giauque, and J. Robert Oppenheimer. Dr. Seaborg was a strong pro ponent of education. He was committed to science education and to the creation of a scientifically literate society.
Answer to Social Studies Activity
The editorials written by students should convey a strong opinion either for or against the Manhattan Project and should incorporate infor-mation found through research to support that opinion. Students should not simply report the information that they find.
Chapter 12 • Science in Action 359