What is radioactivity?

What is radioactivity?

• A. The process by which atoms gain energy
• B. The process by which unstable nuclei emit radiation
• C. The splitting of atoms into heavier elements
• D. The transfer of electrons between atoms

Answer: (C)

Radioactivity is the spontaneous emission of radiation from unstable atomic nuclei. When a nucleus is not in a stable configuration, it can release energy by emitting particles or photons to move toward a more stable state. The emitted radiation includes alpha particles, beta particles, or gamma rays, and the nucleus may change to a different element or isotope in the process—for example, uranium-238 can emit an alpha particle and become thorium-234, while carbon-14 undergoes beta decay to nitrogen-14. This decay happens at a characteristic rate described by a half-life, largely unaffected by ordinary environmental conditions. The other descriptions aren’t correct because gaining energy isn’t what radioactivity refers to, splitting atoms into heavier elements doesn’t describe how radioactive decay works (fission produces lighter fragments), and transferring electrons between atoms is a chemical process, not a nuclear one.

Radioactivity is the spontaneous emission of radiation from unstable atomic nuclei. When a nucleus is not in a stable configuration, it can release energy by emitting particles or photons to move toward a more stable state. The emitted radiation includes alpha particles, beta particles, or gamma rays, and the nucleus may change to a different element or isotope in the process—for example, uranium-238 can emit an alpha particle and become thorium-234, while carbon-14 undergoes beta decay to nitrogen-14. This decay happens at a characteristic rate described by a half-life, largely unaffected by ordinary environmental conditions. The other descriptions aren’t correct because gaining energy isn’t what radioactivity refers to, splitting atoms into heavier elements doesn’t describe how radioactive decay works (fission produces lighter fragments), and transferring electrons between atoms is a chemical process, not a nuclear one.