Cambridge IGCSE Chemistry Coursebook 4th Edition | PDF ... 2.1 The states of matter 22 6 Quantitative chemistry 151 2.2 Separating and purifying substances 27 6.1 Chemical analysis and formulae 152 2.3 Atoms and molecules 34 6.2 The mole and chemical formulae 158 2.4 The structure of the atom 41 6.3 The mole and chemical equations 162 2.5 Electron arrangements in atoms 47 6.4 Calculations involving ...