Element vs Compound vs Mixture: what's the difference?
GCSE Chemistry
Three ways to classify matter by what it contains and how it is joined.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Element vs Compound vs Mixture — side by side
| Element | Compound | Mixture | |
|---|---|---|---|
| Made of | One type of atom | Two or more elements chemically bonded | Two or more substances not chemically bonded |
| Chemically joined? | N/A (single element) | Yes | No |
| Separated by | Cannot be broken down chemically | Chemical reaction / electrolysis | Physical means (filtering, distillation) |
| Fixed ratio? | N/A | Yes (fixed formula) | No (any proportion) |
Exam tip — how to tell them apart: Bonded and fixed ratio → compound. Just mixed together and easily separated → mixture. One kind of atom → element.
Common trap: Air and salt water are mixtures, not compounds — nothing is chemically bonded, so they separate by physical means.
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