5.3 The Periodic Table (Pages 194- 206)

Homework: Page 206 # 3, 4, 5Case Study Page 202 #1-3Key Concepts: (Page 206)

• The modern periodic table is organized according to the atomic numbers of the elements.

• When the elements are arranged in order of increasing atomic number, there is a regular pattern in the properties of elements.

• The three main classes of elements are metals, non-metals, and metalloids.

• Metals are usually solids at room temperature, shiny, good conductors, malleable and ductile.

• Nonmetals are usually gases or solids at room temperature, not shiny, poor conductors, brittle, and not ductile. Metalloids share properties of both metals and non-metals.

• Poisoning by metals in the environment is a serious problem. Mercury contamination of fish has severely affected the health and traditional practices of aboriginal peoples.

• In the periodic table, a period is a horizontal row of elements. A group, or family, is a vertical column of elements.

• Elements that are in the same group have similar properties. Four major groups of elements are the alkali metals, alkaline-earth metals, halogens and the noble gases.

1. What is an atomic mass?

• The average mass of the naturally occurring isotopes of an element.

2. Why did Mendeleev not consider the number of subatomic particles as a

way to organize the elements?

• Mendeleev did not organize the elements according to subatomic particles since he did not know about them as they were discovered much later.

3. How is the modern periodic table organized?

• The modern periodic table is organized according to increasing atomic number. The elements are also grouped according to electron shells (levels).

4. What are synthetic elements? Where do you find the synthetic elements in the periodic table?

• Synthetic elements are those elements that have been made by scientists.

• The synthetic elements in the periodic table are found amongst the elements that have atomic numbers more than 93.

5. Copy down Table 5.2MATERIAL STATE AT ROOM

TEMPERATUREAPPEARANCE CONDUCTIVITY MALLEABILITY

AND DUCTILITY

Metals Solid (except for mercury, which is a liquid)

Shiny Good conductors of heat and electricity

Malleable and ductile

Non-metals Some gases and some solids (except bromine, which is a liquid)

Not very shiny Poor conductors of heat and electricity

Brittle and not ductile

Periods and Groups in the Periodic Table:

• The elements are arranged in horizontal rows and vertical columns.

• The correct name for each vertical column is a group.

• Elements in the same chemical family are located in the same group.

• The horizontal rows are called periods.• There are 18 groups and 7 periods in the periodic

table.

Chemical Family Elements and Symbols

Alkali Metals Hydrogen (H), Sodium (Na), Lithium (Li), Potassium (K)

Alkaline Earth MetalsBeryllium (Be), Calcium (Ca), Magnesium (Mg), Strontium (Sr)

Halogens Fluorine (F), Bromine (Br), Astatine (At), Chlorine (Cl), Iodine (I)

Noble Gases Helium (He), Krypton (Kr), Radon (Rn), Neon (Ne), Xenon

(Xe)

The Invention of Chemical Symbols:• The system of chemical symbols that we use

today was first proposed by the Swedish chemist Jons Jacob Berzelius.

• This system was accepted all around the world. It was accepted not only because it provided symbols for all the known elements, but also because it showed how to create symbols for any new element that might be discovered later.

Language Name of Element Symbol

English Hydrogen H

French Hydroge’ne H

German Wasserstoff H

Italian Idrogeno H

Portuguese Hidrogenio H

Spanish Hidrogeno H

Five Rules to Determine the Symbols:

• Rule 1: The first letter of the name of the element.

Examples:

Oxygen 0 Hydrogen H Carbon C

Fluorine F Nitrogen N Boron B

Rule2: The first two letters of the name of the element.

Examples:

Krypton Kr Argon Ar Lithium Li

Nickel Ni Beryllium Be Xenon Xe

Rule 3: The first letter and one later letter of the name of the element.

Examples:

Manganese Mn Radon Rn Chlorine Cl

Magnesium Mg Rubidium Rb Astatine At

Rule 4: Later elements- named after countries, continents, scientists, place of discovery, or planets

Countries and Continents:

Americanium Am Europium Eu Germanium Ge

Polonium Po Francium Fr Indium In

Place of discovery:

Californium Cf Berkelium Bk

Name of scientists:

Einsteinium Es Fermium Ruthorfordium Mendelevium

Name of a Planet:

Plutonium Uranium Mercury Neptunium_____________________________________

Rule 5 The seven metals known to the ancients were called by their Latin names.

Examples:Natrium (Na) SodiumKalium (K) PotassiumHydragyrum (Hg) MercuryAurum (Au) GoldArgentum (Ag) SilverFerrum (Fe) IronPlumbum (Pb) Lead