What is radioactivity?

The spontaneous decay of unstable nuclei emitting radiation.

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  1. The joining of atoms into molecules
  2. The spontaneous decay of unstable nuclei emitting radiation ✔
  3. The reflection of light by metals

Why: Radioactivity is unstable nuclei decaying and emitting particles or rays over time.

Huh, didn't know that: Radioactivity is unstable nuclei decaying and emitting particles or rays over time.

The dad joke
Radioactivity is instability with a release schedule.
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References

Answer: The spontaneous decay of unstable nuclei emitting radiation. Radioactivity is unstable nuclei decaying and emitting particles or rays over time.

  1. Nuclear physics en.wikipedia.org/wiki/Nuclear_physics
    These "radioisotopes" decay over time
    Checked 2026-11-07.

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