Ionic Compounds

Georgia Elizabeth Williams

Introduction to ionic compounds

An ionic compound formed between a metal and a non-metal is called a salt.

e.g. when sodium (Na+) and chlorine (Cl-) form a bond it creates a salt called sodium chloride. This is because sodium is a metal and chlorine is a non-metal.

If then name of a compound ends in '-ate' this shows us that oxygen is present in the compound.

However, if the name of a compound ends in '-ide' this shows us that no extra oxygen is present in the compound.

Compound Ions

Some compound ions are:

Hydroxide (OH-)

Nitrate (NO3+)

Carbonate (CO3 2+)


Use brackets if you need to put a number with any of the compound ions

e.g. Mg(OH)2 is magnesium hydroxide.

Ionic Formula Rules

  • Swap the numbers that give the charge for each ion and write them after the relevant symbol.
  • If the number is 1. don't write it in the formula.
  • If both numbers are the same, don't write them in the formula.

e.g. Copper Nitrate: (Cu2+) and (NO3-) then becomes Cu(NO3)2.

The oppositely charged ions are arranged in a regular way to form giant ionic lattices. Ionic compounds often form crystals as a result.

e.g. sodium chloride as shown in the image below (NaCl)

Big image