What is a pure substance?
What is a pure substance?

In chemistry, a pure substance contains only one element or only one compound, with nothing else mixed into it. A pure element contains atoms with the same number of protons.
Step-by-step lessons covering AQA GCSE Chemistry 8.1.1 Pure substances for Foundation and Higher tier. Each lesson works through exam-style questions in Paper 1 and Paper 2 format. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.