Chemistry · Grades 5–8
Elements, compounds and mixtures · Revision sheet
Separate chemical composition from physical arrangement.
Learn the idea
Element
An element is identified by its number of protons; its atoms can occur alone or in molecules.
Compound
A compound contains chemically combined elements in a characteristic composition.
Mixture
A mixture contains substances together without a single fixed chemical ratio.
Separation
A physical separation uses a property difference without requiring new substances.
Explain without looking
- A pure compound is chemically decomposed. Is this merely sorting an existing mixture?
- Explain why clear appearance does not prove a sample is pure.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.