1. Chapter 12
Section 2 Grouping the Elements
Bellringer
How do you know that a bird is a bird, that a kangaroo is a kangaroo, and that a shark is a shark? What characteristics of each animal help you to tell the animals apart? How can such an analysis of characteristics be applied to elements?

2. Chapter 12
Section 2 Grouping the Elements
Objectives
Explain why elements in a group often have similar properties.
Describe the properties of the elements in the groups of the periodic table.

3. Chapter 12 Group 1: Alkali Metals
Section 2 Grouping the Elements
Group 1: Alkali Metals
Alkali metals are elements in Group 1 of the periodic table. Alkali metal properties:
group contains metals
1 electron in the outer level
very reactive
softness, color of silver, shininess, low density

4. Group 2: Alkaline-Earth Metals
Chapter 12
Section 2 Grouping the Elements
Group 2: Alkaline-Earth Metals
Alkaline-earth metals are elements in Group 2. Alkaline-earth metal properties:
group contains metals
2 electrons in the outer level
very reactive, but less reactive than alkali metals
color of silver, higher densities than alkali metals

5. Group 3–12: Transition Metals
Chapter 12
Section 2 Grouping the Elements
Group 3–12: Transition Metals
Transition metals are in Groups 3–12. Some of the transition metals are shown below.

6. Group 3–12: Transition Metals, continued
Chapter 12
Section 2 Grouping the Elements
Group 3–12: Transition Metals, continued
Properties of Transition Metals vary widely but include:
groups contains metals
1 or 2 electrons in the outer level
less reactive than alkaline-earth metals
shininess, good conductors of electric current and thermal energy

7. Group 3–12: Transition Metals, continued
Chapter 12
Section 2 Grouping the Elements
Group 3–12: Transition Metals, continued
Lanthanides and Actinides Some transition metals from Periods 6 and 7 appear in two rows at the bottom of the periodic table. Elements in the first row are called lanthanides and elements in the second row are called actinides.

8. Chapter 12 Group 13: Boron Group
Section 2 Grouping the Elements
Group 13: Boron Group
Aluminum is the most common element from Group 13. Group 13 properties:
group contains one metalloid and five metals
3 electrons in the outer level
reactive
solids at room temperature

9. Chapter 12 Group 14: Carbon Group Group 14 properties:
Section 2 Grouping the Elements
Group 14: Carbon Group
Group 14 properties:
group contains one nonmetal, two metalloids, and two metals
4 electrons in the outer level
reactivity varies among the elements
solids at room temperature

10. Chapter 12 Group 15: Nitrogen Group Group 15 properties:
Section 2 Grouping the Elements
Group 15: Nitrogen Group
Group 15 properties:
group contains two nonmetals, two metalloids, and two metals
5 electrons in the outer level
reactivity varies among the elements
solids at room temperature (except for nitrogen, which is a gas)

11. Chapter 12 Group 16: Oxygen Group Group 16 properties:
Section 2 Grouping the Elements
Group 16: Oxygen Group
Group 16 properties:
group contains three nonmetals, one metalloids, and one metal
6 electrons in the outer level
reactive
solids at room temperature (except for oxygen, which is a gas)

12. Chapter 12 Group 17: Halogens
Section 2 Grouping the Elements
Group 17: Halogens
Halogens are the elements in Group 17. Group 17 properties:
group contains nonmetals
7 electrons in the outer level
very reactive
poor conductors of electric current, never in uncombined form in nature

13. Chapter 12 Group 18: Noble Gases
Section 2 Grouping the Elements
Group 18: Noble Gases
Noble gases are the elements in Group 18. Group 18 properties:
group contains nonmetals
8 electrons in the outer level (except helium, which has 2)
unreactive
colorless, odorless gases at room temperature

14. Chapter 12
Section 2 Grouping the Elements
Hydrogen
The properties of hydrogen do not match the properties of any single group, so hydrogen is set apart.
a nonmetal
1 electron in the outer level
reactive
colorless, odorless gas at room temperature, low density