Match the following with the correct definition. 1. High-energy light is released from the nucleus of an atom. 2. High-energy particles or rays are emitted by the nuclei of some atoms. 3. Mass number is the sum of the number of these and the number of protons in the nucleus of an atom. 4. This has a mass number of 4 and a charge of 2+. 5. An electron or a positron is released from the nucleus of an atom. 6. A large nucleus splits into two smaller nuclei, releasing energy. 7. These are particles that keep a nuclear chain reaction going. 8. Small atoms join to form a larger nucleus, releasing energy. a. alpha particle d. nuclear radiation g. nuclear fission b. beta particle e. neutrons (used twice) c. gamma rays f. nuclear fusion