A single covalent bond

A single electron

A shared pair of electrons

A single proton

1

2

3

4

There are strong electrostatic forces of attraction between the atoms.

There are strong electrostatic forces of attraction between the shared electron pair and the two bonding nuclei.

Electrons are strong.

Electron pairs are strong.

An onion which has gone bad.

A positive ion.

A negative ion.

A molecule.

Losing or gaining protons.

Losing or gaining neutrons.

Losing or gaining electrons.

Losing or gaining mass.

Contains oxygen only.

Contains sulphur.

Contains oxygen in addition to two other elements.

Contains nitrogen.

1+

2+

2-

1-

S^2-

S²⁺

SO₄^2-

SO₄²⁺

Covalent bonds

Ionic bonds

Strong electrostatic forces of attraction between oppositely charged ions.

Strong electrostatic forces of attraction between electrons.

Magnesium carbonite

Magnesium carbonate

Magnesium carbon

Magnesium carbonide

NaSO₄

NaSO

Na₂SO

Na₂SO₄

Al(CO₃)₃

Al₂(CO₃)₃

Al₃(CO₂)₂

Al₂CO₃

(NH₄)₂OH

NH₄OH

NH₆O

NH₃O

$Fe\ +S\ +2O_2\ \rightarrow\ FeSO_4$

$Fe\ +S\ +O_2\ \rightarrow\ FeSO_4$

$Fe\ +S\ \rightarrow\ FeS$

$Fe\ +2S\ \rightarrow\ FeS_2$