Radioactivity refers to which process?

• A. Immediate break up of an element and emitting of energy
• B. Chemical bonding
• C. Neutron emission only
• D. Fusion

Answer: (A)

Radioactivity is the spontaneous decay of unstable atomic nuclei, where the nucleus transforms into a more stable form and releases energy as radiation or particles. That idea—the nucleus breaking apart and emitting energy—is what the correct option describes. It’s a nuclear change, not a chemical one that involves electrons and bonds between atoms. It isn’t limited to neutron emission alone, since radioactive decay can emit alpha particles, beta particles, or gamma rays (and sometimes neutrons, depending on the isotope). And fusion, which would be two light nuclei combining to form a heavier one, is a different process altogether.