Video Transcript
Although it is carefully controlled, once nuclear fission is initiated in a nuclear reactor, the reaction continues indefinitely until the fuel rods are spent. What is the name for a reaction of this type? (A) Neutron reaction, (B) decay reaction, (C) Geiger reaction, (D) chain reaction, or (E) fusion reaction.
Nuclear fission is the splitting of one heavy atomic nucleus into two or more lighter atomic nuclei. When atomic nuclei break apart or are combined, nuclear energy is released. We can harness the energy from the nucleus to generate electrical current at nuclear power plants. The uranium-235 isotope is often used as a fuel for this reaction. The atoms of uranium-235 are bombarded with slow-moving neutrons. The neutron enters the nucleus, becoming uranium-236. The nucleus now contains too many neutrons and is unstable. This causes the nucleus to split. Two smaller nuclei will form. In this example, barium and krypton have formed. Additionally, three neutrons and nuclear energy will be released.
The neutrons that were released can then collide with other uranium-235 atoms, which will then turn into unstable uranium-236 atoms and will split in the same way as before. Each uranium-236 atom will produce energy, two smaller nuclei, and three neutrons. Each of these neutrons can collide with another uranium-235 atom. The same process will occur again. This type of reaction is called a chain reaction. A chain reaction is a reaction that follows the same step or steps repeatedly and indefinitely until the reactants are used up or the reaction is terminated. So the answer to the question “What is the name for a reaction of this type?” is (D) a chain reaction.
