- 11. Nuclear processes are those in which an atomic nucleus changes, including radioactive decay of naturally occurring and human-made isotopes, nuclear fission, and nuclear fusion. As a basis for understanding this concept:
- a. Students know protons and neutrons in the nucleus are held together by nuclear forces that overcome the electromagnetic repulsion between the protons. Ch. 25.2
- b. 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. Ch. 25.4
- c. Students know some naturally occurring isotopes of elements are radioactive, as are isotopes formed in nuclear reactions. Ch. 25.2, 25.3
- d. Students know the three most common forms of radioactive decay (alpha, beta, and gamma) and know how the nucleus changes in each type of decay. Ch. 25.1, 25.2
- e. Students know alpha, beta, and gamma radiation produce different amounts and kinds of damage in matter and have different penetrations. Ch. 25.1, 25.2
- f.* Students know how to calculate the amount of a radioactive substance remaining after an integral number of half lives have passed. Ch. 25.3
- g.* Students know protons and neutrons have substructures and consist of particles called quarks.