Science·Matter & Materials·conceptual
Pure Substances & Mixtures
Distinguish between pure substances and mixtures, identify formulations as useful mixtures with precise compositions, and use melting and boiling points to test for purity
Suggested ages 11–13
Evidence of understanding
- Explains why a pure substance has a sharp, fixed melting point but a mixture melts over a range
- Identifies common formulations (medicines, alloys, paints, fuels) as deliberate mixtures
- Explains what impurities do to melting and boiling points
- Distinguishes mixtures from compounds at the particle level
Assessment prompt
If Pure Substances & Mixtures was checking whether a sample of water was pure, could they explain one test they could do — and say what result would tell them it was definitely pure versus a mixture?
Standards alignment
KS3.Sci.Chem.PIS.1GB · uk-nc-2013
Concept of a Pure Substance
The national curriculum in England: Key stages 1 and 2 framework document · KS3
KS3.Sci.Chem.PIS.3GB · uk-nc-2013
Identification of Pure Substances
The national curriculum in England: Key stages 1 and 2 framework document · KS3
KS3.Sci.Chem.PIS.4GB · uk-nc-2013
Formulations
The national curriculum in England: Key stages 1 and 2 framework document · KS3