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The Periodic Table

Copyright © 2010 McGraw-Hill Ryerson Ltd.

How are properties of atoms used to organize elements into the periodic table?

How are properties of atoms used to organize elements into the periodic table?

Topic Topic 2.42.4

(Pages 120-129)

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Copyright © 2010 McGraw-Hill Ryerson Ltd.

The periodic table is a chart in which elements are listed horizontally in order of their atomic number and in which elements with similar properties are arranged vertically.

Elements are arranged in the periodic table according to their atomic structure and properties.

Elements are arranged in the periodic table according to their atomic structure and properties.

How Elements are Arranged

• period a horizontal row in the periodic table

• group a vertical column in the periodic table; also called a family

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2

3

4

5

6

7

1

2 13 14 16 17

18

15

3 4 65 7 9 11 128 10

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Chemical Families

Alkali Metals (Group 1)

– Highly reactive metals e.g. Li, Na, K

Alkaline Earth Metals (Group 2)

– Reactive, but not as much as the halogens and the alkali metals e.g. Be, Mg, Ca

Halogens (Group 17)

– Highly reactive non-metals e.g. F, Cl, Br

Noble Gases (Group 18)

– Stable; do not react with other elements e.g. He, Ne, Ar

Elements in the same family (group) have similar chemical and physical properties because those properties are determined by the element’s atomic structure.

Trends in the Periodic Table

• Based on an element’s location in the periodic table we can determine certain characteristics– i.e. reactivity, electron arrangement

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Reactivity

• The most reactive metals are in group 1

• Reactivity increases as you move down the family

Cesium (Cs) is most reactive.

ReactivityReactivity

Fluorine (F) is most reactive.

• The most reactive nonmetals are in group 17

• Reactivity increases as you move up the family

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Copyright © 2010 McGraw-Hill Ryerson Ltd.

Periods represent the number of energy levels that contain electrons.

Groups represent the number of electrons in the outermost energy level.

Energy Levels and ElectronsEnergy Levels and Electrons

This version of the periodic table includes photos of common elements and the faces of people who either discovered the element or added to our understanding of it.

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Copyright © 2010 McGraw-Hill Ryerson Ltd.

Key Concepts to be reviewed:•Elements are arranged in the periodic table according to their atomic structure and properties.

• Elements in the same family (group) share similar physical and chemical properties.

Topic 2.4 ReviewTopic 2.4 Review