Families of Elements

Section 3.3

Major Classifications• Metals

– Shiny solids– Easy to stretch and shape– Good conductors of heat and electricity– Usually form CATIONS

• Semiconductors– Intermediate conductors of heat and electricity– Usually form CATIONS

• Nonmetals– Solids, liquids, or gases– Solids are usually dull and brittle– Poor conductors of heat and electricity– Usually form ANIONS

Alkali Metals

Alkali Metals

• Group 1 (first vertical column)• All are relatively soft metals• All are highly reactive (explode in water)• All have one valence electron (one electron in

their outer shell)• All form cations with a +1 charge when they

lose that valence electron

Alkaline Earth Metals

Alkaline Earth Metals

• Group 2 (second vertical column)• All are reactive, but less-reactive than Alkali

metals• All have two valence electrons (two electrons

in their outer shell)• All form cations with a +2 charge when they

lose those valence electrons

Transition Metals

Transition Metals

• Groups 3 to 12 • Much less reactive than Alkali Metals or

Alkaline Earth Metals• Some have different numbers of valence

electrons• All form cations• Many different cations are possible for any

one element (Au+, Au3+)

Halogens

Halogens

• Group 17• Highly reactive, especially with alkali metals• Range from gas to liquid to solid as you move

down the column• All form diatomic molecules (like Cl2)

• All form anions with a charge of -1.

Noble Gases

Noble Gases

• Group 18• All are inert, or unreactive• All are gases• All have full valence electron shells• Most do not form cations or anions, but

remain as atoms.