# Explain why elements in Group 1 of the periodic table become more reactive as you go down the group. In your answer, refer to atomic structure and the loss of electrons.

> Edexcel A-Level Chemistry (9CH0) — Topic 2 Inorganic chemistry and the Periodic Table · Explain · 5 marks

> Group 1 elements, known as the alkali metals, are all reactive metals that react vigorously with water. Their reactivity changes as you move down the group from lithium to caesium.

## Mark scheme (5 marks)

1. Group 1 atoms react by losing one outer electron
2. As you go down the group, the atoms get larger / have more electron shells
3. The outer electron is further from the nucleus as you go down the group
4. There is more shielding of the outer electron by inner shells of electrons
5. The outer electron is lost more easily, so reactivity increases down the group

## Key terms

- [Group 1](https://www.gradenine.co.uk/glossary/group-1)

## 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/explain-why-elements-in-group-1-bbc4b24c) · Published by Druglandscape Ltd.