Chapter- 3 Atoms and Molecules 3.3 What is a molecule 3.4 Writing chemical formulae 3.5 Molecular mass Chapter- Structure of The Atom 4.1 Charged particles in matter 4.2 The structure of an atom 13 Chapter- Work and Energy 10.2 - Energy 10.3 - Rate of doing work 13 Chapter- 12 Improvement in Food Resources 12.1 Improvement in Crop Yields 12.1.1 Crop Variety Improvement 12.1.2 Crop Production Management 12.1.3 Crop Protection Management