## Overview This topic discusses the relationship between mass and energy and learners use the equation E = mc2 . Learners are shown how to calculate the binding energy per nucleon of a nucleus and relate this to the stability of the nucleus. The conservation of mass/energy is applied to particle interactions and the physics of fission and fusion is explored. ## Working Scientifically There are opportunities within this topic for learners to comment on experimental design and evaluate scientific methods; to present data in appropriate ways; to process and analyse data using appropriate experimental skills. ## Mathematical Skills There is an opportunity for learners to understand simple probability in this topic. How Science Works There are opportunities within this topic for learners to use knowledge and understanding to pose scientific questions, define scientific problems, present scientific arguments and scientific ideas; to consider applications and implications of science and evaluate their associated benefits and risks; to evaluate the ways in which society uses science to inform decision making. Learners can be given the opportunity to consider and evaluate the benefits and risks to society of the commissioning, building and siting of nuclear power stations. The ethical issues involved in the treatment of the surrounding environment can be considered and the way in which society uses the knowledge and understanding of science to inform decision making. ### Learners should be able to demonstrate and apply their knowledge and understanding of: (a) the association between mass and energy and that E = mc2 (b) the binding energy for a nucleus and hence the binding energy per nucleon, making use, where necessary, of the unified atomic mass unit (u) (c) how to calculate binding energy and binding energy per nucleon from given masses of nuclei (d) the conservation of mass / energy to particle interactions – for example: fission, fusion (e) the relevance of binding energy per nucleon to nuclear fission and fusion making reference when appropriate to the binding energy per nucleon versus nucleon number curve