regents chemistry topic review...

Regents Chemistry

Topic Review Packet

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Table of Contents Topic 1: Matter, Its Properties & Changes

Outline 3 Practice Questions 5

Topic 2: Atomic Concepts Outline 8 Practice Questions 10

Topic 3: Periodic Table Outline 17 Practice Questions 19

Topic 4: Formulas & Names, Equations, Moles, Molar Mass, & Types of Reactions


Topic 5: Bonding Outline 33 Practice Questions 35

Topic 6 Overview 42 Topic 6A: Heat & Temperature


Topic 6B: Kinetics & Equilibrium Outline 50 Practice Questions 5 1

Topic 7: Water & Solutions Outline 55 Practice Questions 56

Topic 8: Acids & Bases Outline 6 1 Practice Questions 62

Topic 9: Organic Chemistry Outline 66 Practice Questions 67

Topic 10: Phases & Gases Outline 7 1 Practice Questions 72

Topic 1 1 : Electrochemistry (Oxidation-Reduction) Outline 75 Practice Questions 76

Answer Key 83

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Topic 1 : Matter, Its Properties and Changes Outline 1. Matter is classified as a pure substance or a mixture of substances. A pure substance (element or compound) has a constant composition and constant properties throughout a given sample, and from sample to sample.

^ You can use particle models/diagrams to differentiate among elements, compounds, and mixtures.

2. The proportions of components in a mixture can be varied. Each component in a mixture retains its original properties. Differences in properties such as density, particle size, molecular polarity, boiling point and freezing point, and solubility permit physical separation of the components of the mixture.

< Methods of separating mixtures include evaporation, filtration, distillation, and chromatography. Mixtures can be homogeneous or heterogeneous. Solutions are always homogeneous. Heterogeneous mixtures are things like soil, fruit salad, where the composition is NOT uniform throughout the mixture.

3. The structure and arrangement of particles and their interactions determine the physical state of a substance at a given temperature and pressure.

^ Know the states (phases) of the elements at STP; Br and Hg are the only 2 liquids, the noble gases as well as N, 0, F, H, and CI are gases, the rest are solids Know the 7 elements that are diatomic in their natural states; "7-Up" or "HOFBrlNCI". Draw particle models of solids, liquids, and gases.

4. A physical change results in the rearrangement of existing particles in a substance; no new types of particles result from this type of change. A chemical change results in the formation of different particles with changed properties.

< Distinguish between chemical and physical changes based on whether new substances form or not.

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5. Properties can be physical or chemical. Physical properties describe those characteristics that can be observed with the senses or measured. Chemical properties describe how the substance interacts with other substances.

Distinguish between chemical and physical properties. One of the more useful properties is density. The densit/ equation is on Table T; D=m/V.

^ Some common properties of the elements are found on Table S, such as melting and boiling points.

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M a t t e r - C u t f r o m J a n 2 0 0 7 - J a n 2 0 0 8 E x a m s

1. A sample composed only o f atoms having the same atomic number is c lass i f ied as

( 1 ) a compound (3) an element (2) a soUition (4) an isomer

2. A dilute, aqueous polassium nitrate solut ion is best c lass i f ied as a ( 1 ) homogeneous compound (2) homogeneous mixture (3) heterogeneous compound (4) heterogeneous mixture

3. A t wh i ch C e l s i u s temperature does lead change from a sol id to a l iquid?

( 1 ) 874V (3) 328°C (2) 6 0 1 T ( 4 ) 0 ° C

8. W h i c h element is a sol id at S T P and a good conductor o f e lectr ic i ty?

( 1 ) iodine ( 3 ) n icke l (2) mercury (4) sul fur

9. T h e table be low shows mass and vo lume data for four samples o f substances at 298 K and 1 atmosphere.

M a s s e s a r td V o l u m e s o f F o u r S a m p l e s

S a m p l e M a s s (gi V o l u m o (r r iL)

A 3 0 . 6 0 .

B 40 . 5 0 .

C 45 9 0 .

D W . 1 2 0 .

4. W h i c h statement describes a chemica l property o f hydrogen gas? ( 1 ) Hydrogen gas bums in air. (2) Hydrogen gas is color less. ( 3 ) Hydrogen gas has a density o f 0.000 09 g /cm ' al S T P . (4) Hydrogen gas has a boi l ing point o f 20. K at standard pressure.

5. \KTi ich element has the greatest density at S T P ? (1) ca l c ium ( 3 ) chlor ine (2) carbon (4) copper

6. W h i c h statement describes a chemica l property o f the element magnes ium? ( 1 ) Magnes ium is mal leable. (2) Magnes ium conducts e lectr ic i ty . ( 3 ) Magnes ium reacts with an ac id . (4) Magnes ium has a high bo i l i ng point.

7. Matter that is composed o f two or more different elements c h e m i c a l l y combined in a fixed proportion is c lass i f i ed as

( 1 ) a compound ( 3 ) a mi.\ture (2) an isotope (4) a solut ion

W h i c h two samples could consist o f the same substance?

{\)AandB ( 3 ) / y a n d C (2) A and C (4) C and D

10. B ronze contains 90 to 95 percent copper and 5 to 10 percent t in. Because these percentages can vary, bronze is c lass i f ied as

( 1 ) a compound ( 3 ) a mixture (2) an element (4) a substance

I I . At S T P , w h i c h list o f elements contains a sol id, a l iquid, and a gas?

{ l ) H f , H g . He ( 3 } B a , B r : , B ( 2 ) C r , C b , C ( 4 ) S e , S n . S r

12. A 10.0-gram sample o f w h i c h element has the swallesi vo lume al S T P ?

(1) a luminum ( 3 ) l i tani iun (2) magnes ium (4) z inc

13. At room temperature, a mixture o f sand and water can be separated by

( 1 ) ionizat ion ( 3 ) filtration (2) combust ion (4) subl imat ion

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14. W h i c h part ic le diagram represents a sample o f one compound, on ly?

( 3 atom ot one elaman' ^ •« atom of a dif?»re*it wl'smenl

Q - c o

° r P C K ^

9 - d »

Q

15. A I.OO-niole sample o f neon gas occup ies a vo lume or24.4 l i ters at 298 K and 101.3 k i lopasca ls . Ca lcu la te the densit>' o f this sample. Y o u r response must inc lude hoih a correct numer ica l setup and the calcu lated result.

B a s e your answers to questions 16 through 18 on the informat ion below.

In an invest igat ion, a dr ip lcss w a x candle is massed and then l ighted. .As the candle bums, a smal l amount o f l iqu id w a x fomis near the t lamc. A f te r 10 minutes, the cand le ' s f lame is ext ingu ished and the candle is a l lowed to cool . T h e cooled candle is massed.

16. Identify one phys ica l change that takes place in this invest igat ion.

17. State om obser\ 'ation that indicates a chemica l change has occurred in this invest igat ion.

18. D r a w a part icle diagrajn show ing the change fi-om sol id w a x to l iquid w a x . Use for par t i c les o f w a x .

D r a w separate d iag rams for the l i qu id and the so l i d s la tes .

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B a s e y o u r a n s w e r s to quest ions 19 through 21 on the par t ic le d iagrams be low , w h i c h s h o w a toms a n d / o r mo lecu les in three d i f ferent samples o f matter at S T P .

® atom o ! * • »l<xr. 01 y

O a tom of J"

o

, , o "

o •

Sampte 1 Stmpts 2

19. W h i c h samp le represents a pure subs tance?

S a m p l e 3

20 . W h e n I w o atoms o f y react w i th one atom o f z , a compound forms. U s i n g the number o f atoms s h o w n in samp le 2 , what is the m a x i m u m number o f m o l e c n l e s o f this compound thai can be f o m i e d ?

2 1 . E x p l a i n w h y , \ does not represent a compound .

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Topic 2: Atomic Concepts Outline 1. The modern model of the atom has evolved over a long period of time through the work of many scientists. ^ Oa/ton's/We/:

• Elements are made of atoms • Atoms of an element are the same. • Compounds are formed from combinations of atoms.

/ût/êrfiyxl B^r/ment • Bombarded gold foil with alpha particles. Showed atoms

were mostly empty space with small, dense positively charged nucleus.

Bo/ir/We/ • Small, dense, positively charged nucleus surrounded by electrons in circular orbits.

He i/e-/4ec/)a/7/ca/ /^c/e/ f/Wem A & w c T/teoryJ • Small, dense, nucleus positively charged nucleus

surrounded by electrons moving in "electron cloud". • "Orbitals" are areas where an electron with a certain amount of energy is njost/i/ê/y

to be found.

2. Each atom is made of a positively charged nucleus with one or more orbiting, negatively charged electrons.

3. Protons and neutrons are found in the nucleus. ^ The number of protons in an atom's nucleus gives the nucleus a positive charge. Li has

a "nuclear charge" of +3, since it has 3 protons.

4. Protons have a positive charge, neutrons no charge, and electrons a negative charge.

5. The number of protons in an atom equals the number of electrons. ^ The positive charges of the protons are cancelled by the negative charges of the electrons,

so overall an atorn has a neutral charge.

6. The mass of a proton is 1 amu. The mass of a neutron is 1 amu. The mass of an electron is almost 0 amu.

The mass of an atom is contained in its nucleus. The atomic mass of an atom is equal to the total number of protons and neutrons.

7. Each electron in an atom has its own distinct amount of energy. ^ When all electrons are at their lowest possible energy, it is called the "ground state." ^ Electrons fill in energy levels and orbitals starting with the one that requires the least energy

and progressively move to those levels and orbitals that require increasing amounts of energy.

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8. When the electron gains a specific amount of energy, it moves to a higher orbital and is in the "excited state".

^ You can recognize an excited state electron configuration. If the configuration does not match that on the Periodic Table for that number of electrons, then it is an excited state.

9. When an electron returns from a higher energy state to a lower energy state, it emits a specific amount of energy usually in the form of light. This can be used to identify an element (bright line spectrum).

The instrument used to see the bright line spectrum is called a spectroscope.

10. The outermost electrons are called valence electrons. These affect the chemical properties of the element.

Atoms with a filled valence level are stable (noble gases). ^ Most elements can have up to 8 electrons in their valence level. The exceptions are H and

He, which can have only 2 valence electrons. Atoms form bonds in order to fill their valence levels. You can use Lewis structures to show the configuration of the valence electrons.

11. Atoms of the same element all contain the same number of protons. Changing the number of protons changes the atom into a different element.

^ The atomic number is the number of protons in an atom of an element.

12. Isotopes are atoms with equal numbers of protons but different numbers of neutrons.

Isotopes of an element have the same atomic number (protons only), but different atomic masses (protons + neutrons).

13. The average atomic mass of an element is the weighted average of its naturally occurring isotopes. ^ You need to know how to do the calculation of "weighted atomic mass" given isotope

masses and percent abundances.

14. When an atom gains an electron, it becomes a negative ion and its radius increases.

15. When an atom loses an electron, it becomes a positive ion and its radius decreases.

16. Electroneaativitv indicates how strongly an atom of an element attracts electrons in a chemical bond. These values are based on an arbitrary scale. > Fluorine has the highest electronegativity of all elements (4.00).

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Atomic Structure - Practice Questipng 1. Experiments performed to reveal the structure of atoms led scientists to conclude that an

atom's (1) positive charge is evenly distributed throughout its volume (2) negative charge is mainly concentrated in its nucleus (3) mass is evenly distributed throughout its volume (4) volume is mainly unoccupied

2. The modern model of the atom shows that electrons are (1) orbiting the nucleus in fixed paths (2) found in regions called orbitals (3) combined with neutrons in the nucleus (4) located in a solid sphere covering the nucleus

3. An experiment in which alpha particles were used to bombard thin sheets of gold foil led to the conclusion that an atom is composed mostly of

(1) empt/ space and has a small, negatively charged nucleus (2) empty space and has a small, positively charged nucleus (3) a large, dense, positively charged nucleus (4) a large, dense, negatively charged nucleus

4. What is the atomic number of an element that has six protons and eight neutrons? (1)6 (2 )2 (3)8 (4)14

5. An atom of fluorine has a mass of 19 atomic mass units. The total number of protons and neutrons in its nucleus is (1 )9 (2)10 (3)19 (4)28

6. What is the total number of protons contained in the nucleus of a carbon-14 atom? (1 )6 (2 )8 (3)12 (4)14

7. What is the nuclear charge of an iron atom? ( l ) +26 (2)+30 (3)+56 (4)+82

8. Which of these elements has an atom with the most stable outer electron configuration? ( l )Ne (2) CI (3)Ca (4) Na

9. How many electrons are in the outermost principal energy level of an atom of carbon in the ground state? (1)6 (2 )2 (3)3 (4 )4

10. Which electron configuration is correct for a sodium ion? (1)2-7 (2)2-8 (3)2-8-1 (4)2-8-2

11. What is the electron configuration of a sulfur atom in the ground state? (1)2-4 (2)2-6 (3)2-8-4 (4)2-8-6

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12. The nucleus of which atom contains 48 neutrons? (1) ;-S (2) tl' (3) ^^lih (4) 'liCcI

13. The number of neutrons in the nucleus of an atom can be determined by (1) adding the atomic number to the mass number (2) subtracting the atomic number from the mass number (3) adding the mass number to the atomic mass (4) subtracting the mass number from the atomic number

14. When an atom loses an electron, the atom becomes an ion that is (1) positively charged and gains a small amount of mass (2) positively charged and loses a small amount of mass (3) negatively charged and gains a small amount of mass (4) negatively charged and loses a small amount of mass

15. In which pair of elements do the nuclei of the atoms contain the same number of neutrons? (1) and (3) n'A'o and ^^Mg (2) ',',v and 'to (4) and ,',V7

16. The characteristic spectral lines of elements are caused when electrons in an excited atom move from

(1) lower to higher energy levels, releasing energy (2) lower to higher energy levels, absorbing energy (3) higher to lower energy levels, releasing energy (4) higher to lower energy levels, absorbing energy

17. Which Lewis electron-dot structure is drawn correctly for the atom it represents?

(1 ) :n ( 3 ) : o :

( 2 ) -F'- i./i) : N g :

18. When a lithium atom forms a Li* ion, the lithium atom (1) gains a proton (3) loses an electron (2) loses a proton (4) gains an electron

19. What is the total number of electrons in the valence shell of an atom of aluminum in the ground state? (1 )8 (2 )2 (3)3 (4)10

20. An electron in an atom moves from the ground state to an excited state when the energy of the electron (1) increases (2) decreases (3) remains the same

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21. During a flame test, ions of a specific metal are heated in the flame of a gas burner. A characteristic color of light is emitted by these ions in the flame when the electrons

(1) emit energy as they move to higher energy levels (2) emit energy as they return to lower energy levels (3) gain energy as they move to higher energy levels (4) gain energy as they return to lower energy levels

22. What is the total number of electrons in a Cu* ion? (1)36 (2) 29 (3)30 (4) 28

Base your answers to questions 23 and 24 on the information and the bright-line spectra represented below.

Many ac/\/&tsing signs depend on the proc/ucb'on of light emissions fhyn gas-fr/ied glass tubes that are subjected to a high-K>ltage source, in^hen light emissions are passed through a ^sectroscope, bright-line spectra are produced-

G a s A I

G a s B

G a s C

Q a s D

Onknov«i r i — — — j j - r — — - p - j mixturo I f I

23. Identify the two gases in the unknown mixture.

24. Explain the production of an emission spertrum in terms of the energy states of an electron.

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A t o m i c C o n c e p t s R e v i e w - C u t f r o m J a n 2 0 0 7 - J a n 2 0 0 8 E x a m s

1. W h i c h subatomic part ic les are located in the nucleus o f a neon atom?

( 1 ) electrons and posi trons ( 2 ) electrons and neutrons q(3) protons and neutrons ( 4 ) protons and electrons

2. T h e total mass o f the protons in an atom o f gold-198 is approximate ly

( 1 ) 79 atomic mass units ( 2 ) 119 atomic mass uni ts ( 3 ) 198 atomic mass uni ts ( 4 ) 277 atomic mass uni ts

3. In a ca l c ium atom in the ground slate, the electrons that possess the least amount o f energy are located in the

( I ) first electron shel l q{2) second electron shel l q(3) third electron shel l ( 4 ) fourth electron shel l

4. W h i c h group o f atomic mode ls is l isted in h is lonca l order f rom the earl iest to the most recent? ( 1 ) hard-sphere modeh wave-mechan ica l model, e lectron-shel l model ( 2 ) hard-sphere model , e lectron-shel l model , wave -mechan ica l model ( 3 ) electron-shel l model , w a v e - m e c h a n i c a l model , hard-sphere model ( 4 ) electron-shel l model , hard-sphere model , wave -mechan ica l model

5 W h i c h isotopic notation represents an atom o f carbon-14?

( I ) tc &) ,«c m | c (4)

6. Wh ich isotopic notation identi f ies a metal lo id thai is matched w i th Ihe corresponding number o f protons in each o f its atoms?

(1) ^Mg and l£ protons (2) ^Siancl Upiotoi is (3) iincl 75 |:irot0iKs

7. Acco rd ing to the wave-mechan ica l model o f the atom, electrons in an atom

( 1 ) t ravel in defined c i rc les ( 2 ) are most l ike ly found in an exc i ted slate ( 3 ) have a posit ive charge ( 4 ) are located in orbitals outside the nucleus

8. What is the total charge o f the nuc leus o f a carbon atom?

( 1 ) - 6 ( 3 ) + 6 ( 2 ) 0 ( 4 ) + 1 2

9. A sample composed only o f atoms hav ing the same atomic number is c lass i f ied as

( 1 ) a compound ( 3 ) an element ( 2 ) a solut ion ( 4 ) an isomer

10. Wh ich two part icles each have a mass approximate ly equal to one a lomic mass uni t?

( 1 ) electron and neutron ( 2 ) electron and positron ( 3 ) proton and electron ( 4 ) proton and neutron

11 . W l i i ch electron conf igurat ion could represent a strontium atom in an exci ted state?

( 1 ) 2 - 8 - 1 8 - 7 - 1 ( 3 ) 2 - 8 - 1 8 - 8 - 1 ( 2 ) 2 - 8 - 1 8 - 7 - 3 ( 4 ) 2 - 8 - 1 8 - 8 - 2

12. What is the total number o f neutrons in an atom

( 1 ) 26 ( 3 ) 5 7 ( 2 ) 31 ( 4 ) 8 3

13. What is the total number o f electrons in a

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M g * - ion? ( 1 ) 10 ( 3 ) 1 4 (2) 12 ( 4 ) 24

e lement? ( 1 ) atomic number ( 3 ) hal f - l i fe ( 2 ) a tomic mass ( 4 ) molar vo lume

14. What w a s concluded about the structure o f the atom as the result o f the gold foi l exper iment? ( 1 ) A pos i t ive ly charged nuc leus is surrounded by pos i t ive ly charged pan ic les . ( 2 ) A pos i t ive ly charged nuc leus is surrounded by most ly empty space. ( 3 ) A negat ive ly charged nucleus is su i rounded by posi t ive ly charged part ic les. ( 4 ) A negat ive ly charged nuc leus is surrounded by most ly empty space.

15. A n atom is e lect r ica l ly neutral because the ( 1 ) number o fp ro tons equals the number o f electrons ( 2 ) number o fp ro tons equals the number o f neutrons ( 3 ) rat io o f the number o f neutrons to the number o f electrons i s 1:1 ( 4 ) rat io o f the number o f neutrons to the number o fp ro tons is 2:1

16. 1 low do the energy and the most probable locat ion o f an e lectron in the third shel l o f an atom compare to the energy and the most probable location o f an electron in the first shel l o f the same atom? ( 1 ) In the third she l l , an electron has more energy and is c loser to the nucleus. ( 2 ) In Ihe third she l l , an electron has more energy and is farther fi-om the nucleus. ( 3 ) In the third she l l , an electron has less energy and is c loser to the nucleus. ( 4 ) (n the third she l l , an electron has less energy and is farther fi-om the nuc leus.

1 7. What is the net charge on an ion that has 9 protons, I 1 neutrons, and 10 electrons?

( 1 ) 1+ ( 3 ) 1 -

(2) 2+ ( 4 ) 2 -

18. WTiich va lue o f an element is ca lcu lated using both the mass and the relat ive abundance o f each o f the natural ly occur r ing isotopes o f this

19. W h i c h two notat ions represent different isotopes o f the same element?

. | ;«Bem,a»( fe ' IN a n d ' J C

& •L i iu„ : l j L i ^4) M r i m c l f ^ S

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B a s e your answers to quest ions 20 through 22 on the infonnat ion below.

T h e accepted vahies for the atomic mass and percent natural abundance o f each natura l ly occurr ing isotope o f s i l icon are g iven in the data table below.

N a t u r a l l y O c c u f r i n g I s o l o p e s S i l i c o n

i s o t o p e A l o m i c M a s s

( a t o m i c m a s s uni ts i P e r c e n t N a t u r a l A b u n d a r ^ c e ( - c )

S i - 2 8 2 7 . 9 8 9 2 . 2 2

S i - 2 9 2 8 . 9 8 4 . 6 9

S i - 3 0 2 9 . 9 7 3 . 0 3

20. Determine the total number o f neutrons in an atom o f S i - 2 9 . [ i ]

2 1 . Show a conec t numer ica l setup for calculat ing the atomic mass o f S i . [ l ]

22. A scientist ca lcu la ted the percent natural abundance o f S i - 3 0 in a sample to be 3 .29%. Deteni i ine the percent error for this va lue, [ i ]

23 . Wri te one electron conf igurat ion for an atom o f s i l i con in an exc i ted state.

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Base your answers to quest ions 24 through 26 on the in fomiat ion below.

AtoETiic Diagrams of Magnesium and Aluminum

K e y

= electron

E lement Le i v i s E lec t ron-Dot D'mgram

E loc t ron -Shc l l D iag ram

niagneisium Mg:

^^^•^ I {(^^^' ^ t

aluminum Al:

24. Ident i fy one piece o f in fonnat ion shown in the electron-shel l d iagrams that is no[ shown in tlie L e w i s electron-dot d iagrams. |[ |

25. Determine the mass number o f Ihe magnes ium atom represented by the electron-shel l d iagram. [ i |

26. E x p l a i n w h y L e w i s electron-dot d iagrams are genera l ly more suitable than e lectron-shel l d iagrams for i l lustrat ing chemica l bonding. [ I I

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Tppic 3: Periodic Table Outline 1. The placement of an element on the Periodic Table gives an indication of the chemical and physical properties of that element.

Elements to the left of the stair step line are metals, and therefore are easily oxidized (lose electrons) in bonding situations, are good electrical conductors, are shiny, malleable, ductile, and have low ionization energies and electronegativities. Elements to the right of the stair step line, but not in Group 18 are nonmetals, and therefore react to gain electrons (get reduced), are not conductors, are dull appearing, brittle, have high ionization energies and electronegativities. Some of the elements along the stair step line have properties of both metals and non-metals and are known as "metalloids" or "semi-metals". Elements in Group 18 are the noble gases and they are chemically inert (unreactive) and have extremely high ionization energies.

2. Elements are arranged in order of increasing atomic number (NOT MASS!)

3. The number of protons in an atom (atomic number) identifies the element. The number of protons in an atom only changes through nuclear reactions.

4. The atomic mass is the sum of protons and neutrons in the nucleus. The mass number given on the periodic table is a weighted average of the different isotopes of that element. Electrons do not significantly add to the atomic mass.

5. Isotopes of an element are identified by the sum of protons and neutrons. Isotopes of the same element have the same number of protons and a different number of neutrons. Examples of isotopic notation are: "eC, " C, carbon-14, C-14

6. Elements can be classified by their properties and their location on the Periodic Table as metals, non-metals, metalloids, and noble gases.

7. Elements may be differentiated by their physical properties. •/ Ex: Densit/, conductivity, malleabilit/, hardness, ductility, solubility

8. Elements may be differentiated by their chemical properties.

Chemical properties describe how an element behaves in a chemical reaction.

9. Elements are arranged into periods and groups.

10. Elements of the same period have the same number of occupied energy levels.

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1 1 . Elements of the same group have the same valence configuration and similar chemical properties. ^ Group 1 elements other than H are alkali rrftala.

Group 2 elements are alkali earth /nefa/s-^ Group 17 elements are halngpris. •I' Alkali metals, alkali earth metals, and halogens all are highly reactive and do not exist as

free elements in nature (they are all found in compounds). ^ Group 18 elements are noNe or inert gases. These elements have filled valence levels and

are do not normally react with other substances.

12. The succession of elements within a group demonstrates characteristic trends in properties. As you progress down a group: ^ atomic radius increases. ^ electronegativity decreases. ^ first ionization energy decreases. ^ metallic character increases.

13. The succession of elements within a period demonstrates characteristic trends in properties. As you progress aeross a group from Igft to right: ^ atomic radius decreases. ^ electronegativity increases.

first ionization energy increases. metallic character decreases.

14. Some elements may exist in two or more forms in the same phase. These forms differ in their molecular or crystal structure, hence their different properties. These different forms are called "allotropes," ^ Ex: Solid carbon exists in three different forms: graphite, diamond (a network solid) and

coal. ^ Ex; the element oxygen can exist in two different forms: O2 gas and ozone (O3 gas)

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Periodic Table - Practice Questions 1. Elements in the Periodic Table are arranged according to their

(1) atomic number (3) relative activity (2) atomic mass (4) relative size

2. Elements in a given period of the Periodic Table contain the same number of (1) protons in the nucleus (3) electrons in the outermost level (2) neutrons in the nucleus (4) occupied principal energy levels

3. Atoms of metals tend to (1) lose electrons and form negative Ions (2) lose electrons and form positive ions (3) gain electrons and form negative ions (4) gain electrons and form positive ions

4. Which properties are most common in nonmetals? (1) low ionization energy and low electronegativit/ (2) low ionization energy and high electronegativit/ (3) high ionization energy and low electronegativity (4) high ionization energy and high electronegativity

5. Which two elements have chemical properties that are most similar? (1) CI and Ar (3) K and Ca (2) Li and Na (4 )CandN

6. Which of the following Period 4 elements has the most metallic characteristics? ( l ) C a (2)Ge (3) As (4) Br

7. If M represents an alkali metal, what is the formula for the compound formed by M and oxygen? C1)M02 (2)M20 (3)M203 (4)M302

8. As the elements in Group 15 are considered in order of increasing atomic number, which sequence in properties occurs?

(1) nonmetal, metalloid, metal (3) metal, metalloid, nonmetal (2) metalloid, metal, nonmetal (4) metal, nonmetal, metalloid

9. Which group contains a metalloid? ( 1 ) 1 (2 )11 (3)15 (4)18

10. As elements of Group 15 of the Periodic Table are considered in order from top to bottom, the metallic character of the atoms of each successive element generally (1) Increases (2) decreases (3) remains the same

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11. Which statement best describes Group 2 elements as they are considered In order from top to bottom of the Periodic Table?

(1) The number of principal energy levels increases, and the number of valence electrons increases.

(2) The number of principal energy levels increases, and the number of valence electrons remains the same.

(3) The number of principal energy levels remains the same, and the number of valence electrons increases.

(4) The number of principal energy levels remains the same, and the number of valence electrons decreases.

12. Which Group 15 element exists as a diatomic molecule at STP? (1) phosphorous (3) bismuth (2) nitrogen (4) arsenic

13. Which Group 16 element when combined with hydrogen forms a compound that would exhibit the strongest hydrogen bonding?

(1) selenium (3) oxygen (2) tellurium (4) sulfur

14. Which ion has the largest radius? ( l ) N a * i2)tAg^* ( 3 )K * (4) Ca^*

15. What occurs as the atomic number of the elements in Period 2 increases? (1) The nuclear charge of each successive atom decreases, and the covalent radius

decreases. (2) The nuclear charge of each successive atom decreases, and the covalent radius

increases. (3) The nuclear charge of each successive atom increases, and the covalent radius

decreases. (4) The nuclear charge of each successive atom increases, and the covalent radius

increases.

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Periodic Table - Cut from J a n 2007 - J a n 2008 Exams

1. W h i c h element is a sohd at S T P and a good conductor o f e lectr ic i ty?

( 1 ) iodine ( 3 ) n i cke l ( 2 ) mercury ( 4 ) sulft ir

2. W h i c h elemeni has boili metal l ic and nonmeial l ic properties?

( 1 ) R b ( 3 ) S i ( 2 ) R n ( 4 ) S r

3. T h e carbon atoms in graphite and the carbon atoms in diamond have difTerent

( 1 ) atomic numbers ( 2 ) atomic masses ( 3 ) electronegat iv i t ies ( 4 ) structural arrangements

4. A toms o f wh i ch e lemeni have the greatest tendency to gain electrons?

( 1 ) bromine ( 3 ) l luor ine ( 2 ) chlor ine ( 4 ) iodine

5. W h i c h statement descr ibes a chemica l property o f the element magnes ium?

( 1 ) Magnes ium is mal leable, ( 2 ) Magnes ium conducts electr ici ty. ( 3 ) Magnes ium reacts w i th an ac id . ( 4 ) Magnes ium has a high boi l ing point.

6. W h i c h statement exp la ins w h y sul fur is c lass i f ied as a Group 16 e lemeni?

( 1 ) A sul fur atom has 6 va lence electrons. ( 2 ) A su lh i r atom has 16 neutrons. ( 3 ) Su l f u r is a y e l l o w sol id at S T P . ( 4 ) Su l f i i r reacts w i th most metals.

7. H o w do the atomic radius and meta l l ic properties o f sodium compare to the atomic radius and metal l ic properties o f phosphorus?

( 1 ) Sod ium has a larger atomic radius and is more metal l ic . ( 2 ) Sod ium has a larger a tomic radius and is lessmeta l l i c . ( 3 ) Sod ium has a sma l le r atomic radius and is more meta l l ic . ( 4 ) Sod ium has a sma l le r atomic radius and is less meta l l i c .

8. W h i c h list o f elements consists o f metal lo ids, on ly?

( 1 ) B , A l , G a { 3 ) 0 , S , S e ( 2 ) C , N , P ( 4 ) S i , G e , A s

9. Wh ich general trend is found in Period 2 on the Per iodic Tab le as the elements are considered in order o f increas ing atomic number?

( 1 ) decreasing atomic mass ( 2 ) decreasing electronegativity' ( 3 ) increasing atomic radius ( 4 ) increasing first ionization energy

10. W h i c h Iwo character is t ics are associated with metals? ( 1 ) low first ionizat ion energy' and low electronegativi ty ( 2 ) low first ionizat ion energy and high eIecironegalivit>' ( 3 ) high first ionizat ion energy and low electronegativi ty ( 4 ) high first ionizat ion energy' and high electronegativi ty

11 . W h i c h element is most chemica l ly s im i la r to chlor ine?

( 1 ) A r ( 3 ) F r ( 2 ) F ( 4 ) S

12. W h i c h grouping o f c i rc les , when considered in order fi-om the top to the bottom, best represents ihe relat ive size o f the atoms o f L i , Na , K . and R b , respect ive ly?

( 1 ) ( 2 ) ( 3 ) ( 4 )

13. At S T P , wh i ch element is brittle and not a conductor o f e lectr ic i ty?

( 1 ) S ( 3 ) N a ( 2 ) k ( 4 ) A r

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14. A n atom o f argon rarely bonds to an atom o f another element because an argon atom has

( 1 ) 8 va lence electrons ( 2 ) 2 electrons in the first shel l ( 3 ) 3 electron she l ls ( 4 ) 22 neutrons

15. T h e e lements on the Per iodic Tab le are arranged in order o f increas ing

( 1 ) bo i l ing point ( 3 ) atomic number ( 2 ) electronegat iv i ty ( 4 ) atomic mass

16. W h i c h element i s c lass i f i ed as a nonmetal? { l ) B e ( 3 ) S i ( 2 ) A I ( 4 ) C I

17. So l id sajTiples o f the e lemeni phosphorus can be whi te , b lack, or red in color. T h e var iat ions in color are due lo different

( 1 ) atomic masses ( 2 ) molecu lar structures ( 3 ) ionizat ion energies ( 4 ) nuc lear charges

18. L i th ium and potassium have s im i la r chemica l properties because Ihe atoms o f both elements have Ihe same

( 1 ) mass number ( 2 ) a tomic number ( 3 ) number o f electron shel ls ( 4 ) number o f va lence electrons

19. A t S T P , w h i c h list o f elements contains a so l id , a l iqu id, and a gas?

(1 ) Hf, H g , He ( 3 ) B a . Br2, B ( 2 ) C r . C I : , C ( 4 ) S e . S n . S r

B a s e your answers to quest ions 20 through 22 on the in fonnat ion below.

E lements w i th a lomic numbers 112 and 114 have been produced and their l U P A C names are pending approval . However , an element that wou ld be put between these two elements on the Per iod ic T a b l e has not yet been produced. I f produced, this e lemeni w i l l be identi f ied by the symbo l Uut unti l a n l U P A C name is approved.

20. D r a w a L e w i s electron-dot d iagram for an atom o f Uut . [ i ]

2 1. Detenn ine the charge o f an Uut nucleus. Y o u r response must include hoili the numer ica l value and the sign o f the charge, [ i ]

22, Identity one e lement thai wou ld be chemica l l y s im i la r to Uut. [ l ]

22

Base your answers lo questions 2 3 through 26 on the information below, wh i ch describes the proposed d i scovers 'o f element I 18,

In 1999, a nuclear chemist and his team announced they had d iscovered a new element by crash ing krypton atoms into lead. T h e new element, number 118. was assigned the name ununoct ium and the symbo l Uuo. One possible isotope o f ununoctium cou ld have been U u o - 2 9 1 .

l- lowever, the discovery o f Uuo w a s not con l i rmed because other scient ists could not reproduce the exper imental results published by the nuclear chemist and his team. In 2006, another team o f sc ien l is ts c la imed that they produced Uuo. T h i s c la im has yet to be conf in i ied.

Adapted from Discover January 2002

23 . Based on atomic number, in wh ich group on the Periodic Tab le would element 118 be placed? [ l |

24. What wou ld be the total number o f neutrons present in a thcorei ical atom o f Uuo -291? | I ]

25 . What w o u l d be the total number o f electrons present in a theoretical atom o f Uuo-291? [ i j

26. E x p l a i n w h y being able to reproduce scient i f ic results is an important component o f sc ient i f ic research, [ l ]

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Base your answers to quest ions 27 through 30 on the in fonnat ion below.

T h e table below l is ts phys ica l and chemica l properties o f s i x e lements at standard pressure that correspond to k n o w n elements on the Per iod ic Tab le . T h e elements are identi f ied by the code letters, D, t', G, J. L . and O.

Properties of SJx Elements at Starxlard Pressure

Eicmeît D Element E Elefr.er.1 G E>snsity 0.00018 g cnv-Melttng pofnt ~27TO Boithig point -269-'C Oxkte (ormute (none)

DensHy 1,82 ^-'cnt^ Melting point 44 C Boiling point ms^C Oxide ftifmiia EÔg

Density 0.53 !>'cm^ Melting pdnt 1 8 r c Boiling pomt 1347=^G Oxide lorinula GÔ

Element J Element L E(OT.ent Q Density 0,0013 g<'cm^ Melting point-2 n r c Boiling point Oxkte formula JÔ^

Density 0.86 -g 'cm^ MeHIng point G4*C Boiling point 7?4' 'C Oxide Mytmiia. U O

Den$j^ 0-9T §'cm^ MelTir>g point 9 r c Boiling point 8gi3PC Oxide tonrnjla QÔ

27. What is the total number o f e lements in the "Proper t ies o f S i x E lements at Standard Pressure" table that are sol ids at S T P ? [1]

28. A n atom o f e lemeni G is in the ground slate. What is the total number o f va lence electrons in this a tom?

I I ]

29. Letter Z c o n e s p o n d s to an e lemeni on the Per iodic Tab le other than the s i x l isted elements. E lements G, O, L and Z arc in ihe same group on the Periodic T a b l e , as shown in the d iagram below.

Q T;

Based on the trend in the mel t ing points for elements G . O , and L l isted in the 'Propert ies o f S i x E lements at Standard Pressure" table, est imate the mel t ing point o f e lemeni Z , in degrees

Ce l s i us . [ I ]

30. Identify', by code lei ier, the e lemeni that is a noble gas in the "Proper t ies o f S i x E lemen ts at Standard Pressu re " table. 11]

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regents chemistry topic review...

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