During chemical reactions, there is conservation of mass. During nuclear reactions mass is converted into energy according to Einstein's famous equation E = mc². There are two types of nuclear reactions in which this mass to energy conversion occurs: fission and fusion. In fission reactions, unstable nuclei absorb a neutron and break apart to form two smaller more stable nuclei. In fusion, two small nuclei fuse to form a larger nucleus. This PowerPoint presentation examines the chemistry of fission and fusion. It lists the fissile isotopes, shows a chain reaction, and explains the implications. It also explains why fusion only occurs between small nuclei, and shows both the D-T reaction, and the proton-proton chain. The energy considerations and implications of fusion are discussed. Worksheets on this topic are available free of charge on my website at www.evanschemistrycorner.com.