Catalyst 1Reproduction Environment and feeding relationship Variation and classification Acids and alkalis Simple chemical reactions Particle model of solids, liquids and gases Solutions Energy resources Electrical circuits Forces and their effects The solar system and beyond Glossary Index Catalyst 2Food and Digestion Respiration Microbes and diseases Ecological relationships Atoms and elements Compounds and mixtures Rocks and weathering The rock cycle Heating and cooling Magnets and electromagnets Light Sound and hearing Catalyst 3Inheritance and selection Fit and healthy Plants and photosynthesis Plants and food Reactions of metals and compounds Patterns of reactivity Environmental chemistry Using chemistry Energy and electricity Gravity and space Speeding up Pressure and moments