Which phrase describes radioactive decay?
a) the joining of small nuclei into a larger nucleus
b) the triggering of one reaction by the products of another
c) the splitting of a large nucleus into smaller nuclei
d) the spontaneous emission of radiation
d) the spontaneous emission of radiation.
d) the spontaneous emission of radiation
The correct answer is d) the spontaneous emission of radiation.
To arrive at this answer, let's break down the options and explain why the other choices are not correct:
a) The joining of small nuclei into a larger nucleus is known as nuclear fusion, not radioactive decay. Nuclear fusion involves combining two or more lighter nuclei to form a heavier nucleus, often releasing a significant amount of energy in the process.
b) The triggering of one reaction by the products of another is called a chain reaction. While chain reactions can occur in nuclear processes, they are not specifically related to radioactive decay. Chain reactions involve the products of one reaction initiating subsequent reactions.
c) The splitting of a large nucleus into smaller nuclei is called nuclear fission. Nuclear fission occurs when a heavy nucleus, such as uranium-235, is bombarded with a neutron and then splits into two smaller nuclei, releasing additional neutrons and energy.
d) The spontaneous emission of radiation is the correct description of radioactive decay. Radioactive materials are unstable and undergo radioactive decay, resulting in the spontaneous emission of radiation, which can come in the form of alpha particles (helium nuclei), beta particles (electrons or positrons), or gamma rays (high-energy electromagnetic waves).
In summary, option d) the spontaneous emission of radiation accurately describes the process of radioactive decay.