The conservation checklist
The conservation checklist
A particle interaction is allowed only if the totals before and after match. In A Level particle physics, always check charge QQQ, baryon number BBB, electron lepton number LeL_eLe, muon lepton number LμL_\muLμ, and remember that total energy and total momentum are conserved too.
Step-by-step lessons on AQA A Level Physics Applications of conservation laws. Each one builds up to exam-style questions. Physics is one of the most mathematically demanding A Levels -- at least 40% of the marks require maths skills at Level 2 (GCSE) standard or above, so build calculation and graph-handling fluency alongside the conceptual content from the start.