Section 1 g) Summary

Covalent bonding is the bonding of two non-metal atoms. It involves a shared pair of electrons. The attraction between the nucleus of each of the atoms and the electrons of the other atom creates a very strong covalent bond.

Simple covalent structures usually have low melting and boiling points, and are often fluid at room temperature, because the forces between the molecules are weak and don't require much energy to break. They have weak intermolecular forces.
Examples include: water, oxygen, carbon dioxide, hydrogen chloride, etc.

Giant covalent structures have very high melting and boiling points, because they have so many strong covalent bonds holding the atoms together. It requires a lot of energy to break that many covalent bonds, so they have high melting points.
Examples include: diamond (carbon), graphite (carbon), silicon dioxide, etc.

Dot and cross diagrams can be used to represent covalent bonding. Here are the most important ones for this topic:

Methane

Water

Hydrogen Chloride

Chlorine

Hydrogen

Ammonia

Oxygen

Nitrogen

Carbon Dioxide

Ethane

Ethene