Standard 1d Preknowledge
1d) Students know the energy release per gram of material is much larger in nuclear fusion or fission reactions than in chemical reactions. The change in mass (calculated by E = mc2 ) is small but significant in nuclear reactions.
CALIFORNIA FRAMEWORKS SUMMARY: Two major types of nuclear reactions are fusion and fission. In fusion reactions two nuclei come together and merge to form a heavier nucleus. In fission a heavy nucleus splits apart to form two (or more) lighter nuclei. The binding energy of a nucleus depends on the number of neutrons and protons it contains. A general term for a proton or a neutron is a nucleon. In both fusion and fission reactions, the total number of nucleons does not change, but large amounts of energy are released as nucleons combine into different arrangements. This energy is one million times more than energies involved in chemical reactions.