# Describe how the reactivity of the halogens changes going down Group VII, and explain this trend in terms of electronic structure.

> Cambridge International IGCSE Chemistry (0620) — 8.3 Group VII properties · Describe and Explain · 4 marks

## Mark scheme (4 marks)

1. Reactivity decreases going down Group VII
2. Halogens react by gaining one electron (to complete their outer shell)
3. Going down the group, atoms have more electron shells / the outer shell is further from the nucleus
4. The attraction between the nucleus and an incoming electron is weaker, so it is harder to gain an electron

## Key terms

- [Group VII](https://www.gradenine.co.uk/glossary/group-vii)
- [reactivity](https://www.gradenine.co.uk/glossary/reactivity)

## Related

- [Revision notes for Cambridge International IGCSE Chemistry (0620)](https://www.gradenine.co.uk/learn)
- [How to answer "Describe and Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/describe-how-the-reactivity-of-the-b29a07a6) · Published by Druglandscape Ltd.