Reading chemical formulae
Reading chemical formulae

A chemical formula shows which elements are present and the ratio of their atoms. A symbol with no subscript means one atom, while a subscript shows how many atoms of the element immediately before it are present.
Step-by-step lessons on Edexcel GCSE Chemistry 1.1.1 Formulae, word and balanced equations. Each one builds up to exam-style questions. Nail the core quantitative topics — moles, balancing equations and calculations — early on, since they underpin higher-tier questions across every paper and topic.