Bonding - (CCEA)Page 6

Dot and cross diagrams for covalent bonding

We can use dot and cross diagrams to show how a pair of electrons forms a covalent bond.

Here is the dot and cross diagram for oxygen (O₂), a diatomic molecule. Notice the lone pairs of electrons and the two shared pairs of electrons.

Here are the dot and cross diagrams for some other common molecules.

A single covalent bond is when two atoms share a single pair of electrons. Represented by a single line (–).