Book excerpt: How can a potato be a battery? How quickly will a shark find you? What food should you take with you when climbing a mountain? The Really Useful Book of Secondary Science Experiments presents 101 exciting, ‘real-world’ science experiments that can be confidently carried out by any KS3 science teacher in a secondary school classroom. It offers a mix of classic experiments together with fresh ideas for investigations designed to engage students, help them see the relevance of science in their own lives and develop a passion for carrying out practical investigations. Covering biology, chemistry and physics topics, each investigation is structured as a problem-solving activity, asking engaging questions such as, ‘How can fingerprints help solve a crime?’, or ‘Can we build our own volcano?’ Background science knowledge is given for each experiment, together with learning objectives, a list of materials needed, safety and technical considerations, detailed method, ideas for data collection, advice on how to adapt the investigations for different groups of students, useful questions to ask the students and suggestions for homework. Additionally, there are ten ideas for science based projects that can be carried out over a longer period of time, utilising skills and knowledge that students will develop as they carrying out the different science investigations in the book. The Really Useful Book of Secondary Science Experiments will be an essential source of support and inspiration for all those teaching in the secondary school classroom, running science clubs and for parents looking to challenge and excite their children at home.