# Hydrogen chloride (HCl) and chlorine (Cl₂) are both covalently bonded molecules. Explain how a covalent bond is formed and describe the shapes of these two molecules, including their bond angles.

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

> Hydrogen chloride is a diatomic molecule formed between hydrogen and chlorine. Chlorine gas consists of diatomic molecules in which two chlorine atoms are bonded together.

## Mark scheme (5 marks)

1. A covalent bond is formed by the sharing of a pair of electrons between two non-metal atoms.
2. Each atom contributes one electron to the shared pair.
3. HCl is a linear molecule.
4. The bond angle in HCl is 180°.
5. Cl₂ is also a linear molecule with a bond angle of 180°, because there are only two atoms bonded together / it is a diatomic molecule.

## Key terms

- [covalent bond](https://www.gradenine.co.uk/glossary/covalent-bond)
- [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)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
- [Practice this with AI marking (free)](https://www.gradenine.co.uk/start)

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Source: [GradeNine](https://www.gradenine.co.uk/q/hydrogen-chloride-hcl-and-chlorine-cl-4f1bf61c) · Published by Druglandscape Ltd.