(2.2) The Periodic Table

(p118-121)

Periodic Table of the Elements (p450)

Table Characteristics Metals (LEFT), non-metals (RIGHT)

and metalloids (STAIRCASE LINE)

Periods (or rows)

Groups / Families (or columns)

Common Chemical Groups

There are 18 chemical groups on the periodic table, however four of these groups are of particular interest Alkali metals (group 1) Alkaline earth metals (group 2) Halogens (group 17) Noble gases (group 18)

Alkali Metals Group 1 Soft, silver-grey

metals that react easily with water and with oxygen

NOTE: H is not an alkali metal.

alkali metals in water

Alkaline Earth Metals Group 2 Silver-grey metals

that are harder than group 1 metals.

Reactive atoms (less reactive than group 1 metals) that combine easily with other atoms.

Halogens Group 17 Coloured non-

metals that are VERY reactive

Can be a solid, a liquid or a gas

Noble Gases Group 18 Non-metals that

are colourless, odourless gases.

Unreactive (inert) atoms that do not combine easily with other atoms.

Ion Charge Reactive elements can become stable (full

valence shell) by gaining or losing electrons. An atom that gains electrons becomes a

negatively charged ion called an anion. Non-metals gain electrons. An atom that loses electrons becomes a

positively charged ion called a cation. Metals lose electrons.

Magnesium Ion Mg Mg2+

Magnesium atom loses 2 valence electrons Mg2+ has a full valence shell and is stable

Nitride Ion N N3-

Nitrogen atom gains 3 valence electrons The nitride ion has a full valence shell, so

it is stable

What will the charge be?

CLASS WORK

“Periodic Table Assignment”