This is a complete book for the new OCR specification. Written by a team of experts, including a Chief and Principal Examiner, these new resources contain new and improved content with an emphasis on assessment - exactly what teachers have been asking for. It includes model question and answer sections with feedback, including tips on exam techniques and revision advice direct from examiners. It introduces all-new Apply it! features which give examples to reinforce how the theory being demonstrated is used in real life situations. It is now in full colour to aid accessibility and student engagement.