# Calcium and magnesium are both Group 2 metals. Explain why calcium is a more reactive metal than magnesium, and describe what you would observe when a small piece of calcium is added to cold water.

> Edexcel A-Level Chemistry (9CH0) — 4.1 Group 2 metals · Explain · 5 marks

> Group 2 metals react with water to form metal hydroxides and hydrogen gas. Their reactivity increases down the group.

## Mark scheme (5 marks)

1. Calcium has more electron shells / energy levels than magnesium
2. The outer electron in calcium is further from the nucleus / less strongly attracted to the nucleus
3. Calcium loses its outer electron(s) more easily, so it forms cations more readily
4. Effervescence / bubbles of hydrogen gas are seen (when calcium is added to water)
5. The calcium dissolves / disappears and the solution turns cloudy / milky (calcium hydroxide partially dissolves)

## Key terms

- [Group 2](https://www.gradenine.co.uk/glossary/group-2)

## 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)

---
Source: [GradeNine](https://www.gradenine.co.uk/q/calcium-and-magnesium-are-both-group-d253489e) · Published by Druglandscape Ltd.