These new revision guides, one for Higher tier and one for Foundation, are designed to help your students make the best use of their revision time.* The revision guides are ideal for use in the weeks leading up to the final exam and can also be used throughout the year for additional practice.* Material needed only for double science is indicated in the margin so students studying single science know which material they need.The guides are organised by the underlying scientific concepts of the course rather than the contexts of the unit guides. This will:* help students draw together the concepts developed in the unit guides so that they can apply them effectively to different contexts presented to them in the examination. * help them consolidate the underlying concepts during the course in used as a homework resource.At the start of each unit in the book the concepts are linked to the contexts students have met throughout their course so they are still in familiar territory.