# Explain why alloys are often used in construction and engineering instead of pure metals.

> OCR GCSE Chemistry A: Gateway Science (J248) — C6.1 Improving processes and products · Explain · 4 marks

> Steel is an alloy of iron and carbon. It is widely used in the construction of bridges and buildings, whereas pure iron is rarely used for these purposes.

## Mark scheme (4 marks)

1. An alloy is a mixture/combination of two or more metals (or a metal with another element such as carbon)
2. The different-sized atoms disrupt/distort the regular arrangement of atoms in the metal
3. This makes it harder for layers to slide over each other
4. This gives the alloy greater strength (and/or greater resistance to corrosion) compared to the pure metal

## Key terms

- [alloy](https://www.gradenine.co.uk/glossary/alloy)

## Related

- [Revision notes for OCR GCSE Chemistry A: Gateway Science (J248)](https://www.gradenine.co.uk/learn)
- [How to answer "Explain" questions](https://www.gradenine.co.uk/tools/command-word-cheatsheet)
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Source: [GradeNine](https://www.gradenine.co.uk/q/explain-why-alloys-are-often-used-ad7ec3c6) · Published by Druglandscape Ltd.