Course Introduction This course covers Topic C2.3: Atomic Structure, Analysis and Quantitative Chemistry which is examined on Paper 2 of the GCSE AQA Chemistry Course. This course has three subtopics: 1. Atomic Structure 2. Analysing substances 3. Quantitative Chemistry   The following information, included in this course, is examined at Higher Tier only: The relative atomic mass of an element  Calculating molecular mass using mass spectrometer. Calculating the empirical formula of a compound  from the masses or percentages of the elements in a compound. Calculating the masses of reactants and products from balanced symbol equations. Make sure to attempt the examples yourself first before looking at the solutions!

Reversible Reactions In some chemical reactions, the products of the reaction can react to produce the original reactants. Such reactions are called reversible reactions and are represented: \( A + B \rightleftarrows C+ D\) For example: \( \text{Ammonium chloride}  \rightleftarrows \text{Ammonia + Hydrogen chloride} \)