Which option correctly describes radioactive decay?

• A. A chemical process that releases heat.
• B. It is the process of releasing radiation when an atom splits or decays.
• C. It refers to heat transfer by convection.
• D. It involves the absorption of radiation by the nucleus.

Answer: (B)

Radioactive decay is a nuclear transformation where an unstable nucleus becomes more stable and releases energy as radiation in the process. The best description is that it is the process of releasing radiation when an atom splits or decays. This captures both the emission of particles or photons (like alpha, beta, or gamma radiation) and the nucleus changing toward a more stable configuration. It’s a nuclear event, not a chemical one, which is why it’s associated with radiation emission rather than just heat.

The other ideas don’t fit because they describe different phenomena: a chemical process releasing heat is about electron rearrangements and energy not tied to nucleus changes; convection is a mode of heat transfer and has nothing to do with nuclear radioactivity; absorption of radiation by the nucleus would imply the nucleus taking in energy rather than emitting it during decay.