Absolute clarity is the aim with a new generation of revision guide. This guide has been expertly compiled and edited by subject specialists, highly experienced examiners and a good dollop of scientific research into what makes revision most effective. Past examinations questions are essential to good preparation, improving understanding and confidence. This guide has combined revision with tips and more practice questions than you could shake a stick at. All the essential ingredients for getting a grade you can be really proud of. Each specification topic has been referenced and distilled into the key points to make in an examination for top marks. Questions on all topics assessing knowledge, application and analysis are all specifically and carefully devised throughout this book.