Covalent bonding (AQA GCSE Chemistry Combined Science): Revision Notes

2.1.4 Covalent bonding

Covalent Bonds

Formation:

Covalent bonds form when two non-metal atoms share electrons to achieve a full outer shell.

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Example: In a molecule of water (H₂O), each hydrogen atom shares one electron with the oxygen atom, forming covalent bonds.

$$H - O - H$$

Bonding:

The shared electrons spend time in the outer shells of both atoms, creating a strong bond between them. Covalent bonds result in the formation of molecules.

Properties:

• Covalent compounds have lower melting and boiling points compared to ionic compounds.
• They are often insoluble in water.
• Covalent compounds do not conduct electricity because they do not have free-moving charged particles (ions or electrons).