How the periodic table is arranged
How the periodic table is arranged
The periodic table arranges elements in order of increasing atomic number. Atomic number is the number of protons in an atom, so the order is based on proton number, not relative atomic mass.
Step-by-step lessons covering AQA GCSE Chemistry 1.2.1 The periodic table 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.