What is a half-life?

The time for half of a radioactive sample to decay.

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  1. The time for radiation to travel one meter
  2. The time for half of a radioactive sample to decay ✔
  3. The time for a nucleus to double in size

Why: Half-life is the time in which half the atoms in a radioactive sample decay.

Huh, didn't know that: Half-life is the time in which half the atoms in a radioactive sample decay.

The dad joke
Half-life is a half-and-half kind of timer.
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References

Answer: The time for half of a radioactive sample to decay. Half-life is the time in which half the atoms in a radioactive sample decay.

  1. Scouting America: Nuclear Science www.scouting.org/merit-badges/nuclear-science
    Perform an experiment demonstrating half-life using nonradioactive materials
    Checked 2026-11-07.

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