# Magnesium and calcium are both elements in Group 2 of the periodic table. When each element reacts with cold water, magnesium reacts very slowly whilst calcium reacts more vigorously, producing a metal hydroxide and hydrogen gas. Explain why calcium is more reactive than magnesium, and describe one similarity you would expect in the products formed when each metal reacts with water.

> WJEC A-Level Chemistry (Wales) — 2.2 Group 1, 2 and 7 · Explain · 5 marks

> Magnesium and calcium are both in Group 2 of the periodic table. Magnesium has atomic number 12 and calcium has atomic number 20.

## 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 than in magnesium
3. The outer electrons in calcium are lost more easily (than in magnesium)
4. Both metals produce a metal hydroxide (as one of the products)
5. Both metals produce hydrogen gas (as one of the products)

## Key terms

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

## Related

- [Revision notes for WJEC A-Level Chemistry (Wales)](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/magnesium-and-calcium-are-both-elements-6b4c6e00) · Published by Druglandscape Ltd.