# Explain why ammonia (NH₃) has a low boiling point and does not conduct electricity when it melts.

> Cambridge International IGCSE Chemistry (0620) — 2.5 Simple molecules and covalent bonds · Explain · 4 marks

> Ammonia is a gas at room temperature and is used as a refrigerant. It is a simple covalent molecule with a boiling point of –33 °C.

## Mark scheme (4 marks)

1. Ammonia consists of molecules / is a simple molecular substance
2. There are weak intermolecular forces between the molecules
3. Little energy is needed to overcome these weak intermolecular forces, so the boiling point is low
4. There are no free/mobile electrons or ions present (in any state), so it cannot conduct electricity

## Key terms

- [boiling point](https://www.gradenine.co.uk/glossary/boiling-point)

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-ammonia-nh-has-a-e107bba1) · Published by Druglandscape Ltd.