Relative formula mass
Relative formula mass
Relative formula mass, MrM_rMr, is the sum of the relative atomic masses, ArA_rAr, of all the atoms shown in a chemical formula. Relative atomic mass is a weighted mean that accounts for the natural abundances of an element's isotopes.
Step-by-step lessons on Edexcel GCSE Chemistry 2.6.1 Relative formula mass and percentage composition. 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.