Lesson 1 of 8

Pure substances and mixtures

Goal: Tell a pure substance from a mixture.

Puzzles for this lesson

In science, a pure substance is made of only one substance. A mixture has two or more substances mixed together.

Pure: gold, oxygen and distilled water. Each one is a single element or compound.
Mixtures: air, sea water, milk and fruit juice. A carton may say “pure orange juice”, but to a scientist it is a mixture.
A pure substance melts at one fixed temperature. A mixture melts over a range of temperatures.

Your turn

This lesson’s activity starts here in a moment.

I can say what pure means in science.I can use a melting point to judge whether a substance is pure.

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Pure substance Made of only one substance

Mixture Two or more substances mixed together, not joined

For teachers: AQA 3.5.2 · Pearson Edexcel 12.1 · Cambridge 8Cm.04, 7Cm.04 in part