# Water (H₂O) is a covalently bonded molecule. Explain why a water molecule has a bent (non-linear) shape rather than a straight (linear) shape, and state the bond angle found in a water molecule.

> Edexcel A-Level Chemistry (9CH0) — 2.2 Covalent bonding and shapes · Explain · 5 marks

> Water is essential for life. Each water molecule contains two hydrogen atoms covalently bonded to one oxygen atom. Oxygen has six electrons in its outer shell.

## Mark scheme (5 marks)

1. A covalent bond is formed by a shared pair of electrons (between oxygen and each hydrogen)
2. Oxygen forms two covalent bonds, leaving two lone pairs of electrons on the oxygen atom
3. Lone pairs repel more strongly than bonding pairs
4. The lone pairs push the bonding pairs closer together, bending the molecule away from a linear arrangement
5. The H–O–H bond angle is approximately 104.5°

## Key terms

- [bond angle](https://www.gradenine.co.uk/glossary/bond-angle)

## Related

- [Revision notes for Edexcel A-Level Chemistry (9CH0)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/water-h-o-is-a-covalently-bonded-bb7e6524) · Published by Druglandscape Ltd.