What is radioactivity?
Quick Answer
Radioactivity is the process by which unstable atomic nuclei lose energy by emitting radiation — such as alpha particles, beta particles, or gamma rays — as they transform into more stable forms.
The Full Story
Radioactivity occurs when the nucleus of an unstable atom releases energy and particles to become more stable. There are three main types of radiation: alpha particles, which are heavy and easily stopped by paper or skin; beta particles, which are lighter and can penetrate a little further; and gamma rays, high-energy electromagnetic waves that require thick lead or concrete to block. Each radioactive isotope decays at a characteristic rate described by its half-life, the time it takes for half the atoms to decay. Radioactivity was discovered by Henri Becquerel in 1896 and studied intensively by Marie and Pierre Curie. It occurs naturally in rocks, soil, and even the human body, and it has vital uses in medicine, energy generation, and dating ancient objects, though high doses can damage living cells.
Key Facts
YouTube Angle
Suggested video title for this topic:
"Radioactivity — When Atoms Fall Apart and Release Energy"