This resource is intended for KS3 classes who have some experience of chemical reactions and balancing equations, and who are aware that some reactions give off heat while other take require energy from the environment. The aim is to be able to explain this in terms of the bonds that are formed and broken between atoms.

Two Powerpoint presentations introducing the basics of moments, including the equation used and examples for students to work out. This resource should be especially useful for low ability students. The first file covers a single moment in one direction, and opposing moments on a seesaw are covered in the second. Rearrangement of the equation is also covered with examples to work out.