Unit 1 Forces Unit 2 Solid, liquid, gas states and changes of state Unit 3 Cells Unit 4 Our solar system and beyond Unit 5 Solutions Unit 6 Ecosystems Unit 7 Sound, light and vision Unit 8 Heredity and DNA Unit 9 Separation techniques Unit 10 Human skeleton and muscles Unit 12 Diffusion Unit 13 Human digestive system Unit 14 Atoms, elements and compounds