Science
What is Radioactivity?
Radioactivity is the process where unstable atomic nuclei lose energy by emitting radiation. As these atoms 'decay', they release particles or rays — a process used in everything from nuclear power to medical imaging and carbon dating.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains radioactivity.
Key things to understand
- 1Unstable atomic nuclei release energy as radiation.
- 2This 'decay' can emit alpha, beta, or gamma radiation.
- 3Each radioactive element decays at a steady, known rate (half-life).
- 4It's used in power, medicine, and dating ancient objects.
Frequently asked questions
- What causes radioactivity?
- Unstable atomic nuclei shedding excess energy by emitting particles or rays as they decay.
- What is a half-life?
- The time it takes for half of a radioactive sample to decay — a fixed rate for each element.
- Is all radioactivity dangerous?
- High doses are harmful, but low levels are natural and everywhere; many uses are safe and beneficial.