2.2 Ionic Compounds

2.2.1 Atomic Ions

LO: I understand how ions are formed from neutral atoms

Atoms form ions to achieve a stable electron arrangement:

• Metals form ions

LO: I understand how ions are formed from neutral atoms

• Non-metals form ions

Element

Atom electron arrangement

Ion electron

arrangement

Ion Symbol

sodium

bromine

aluminium

sulphur

2,8,1

2,8,18,7

2,8,3

2,8,6

2,8

2,8,18,82,8

2,8,8

Na+

Br-

Al3+

S2-

positive

negative

2.2.2 Simple Ionic Structures

LO: I understand the structure and bonding in an ionic substance

The ionic bond is the attraction between positive and negative ions.

• An ionic .

LO: I understand the structure and bonding in an ionic substance

• An ionic .

As the size of the ions increases the strength of the ionic bond .

The structure of sodium chloride can be described as:

The ratio of sodium ions to chloride ions is so the formula is .

electrostatic

network

lattice

decreases

1:1NaCl