Radioactive
/ˌreɪdiːoʊˈæktɪv/
Definitions
Having or producing the energy that is released by the breakdown of atoms. This energy is in the form of radiation. Substances that are radioactive release these energetic particles or rays.
/ˌreɪdiːoʊˈæktɪv/
Emitting or relating to the emission of ionizing radiation.
The Chernobyl disaster released radioactive materials into the environment.
💡 Simply: Imagine a lightbulb that's always on, giving off a special kind of energy. Radioactive stuff is like that, but instead of light, it gives off invisible rays. These rays can be helpful in some ways, like in medicine, but also dangerous if not handled carefully.
👶 For kids: Something is radioactive if it's like a tiny lightbulb that gives off invisible beams that can be powerful.
More Examples
Scientists are studying the effects of radioactive waste on marine life.
Radioactive dating uses the decay of radioactive isotopes to determine the age of rocks.
How It's Used
"Uranium is a highly radioactive element."
"Radioactive isotopes are sometimes used in medical treatments."
"The area was contaminated by radioactive fallout."
From the combination of "radio-" (referring to radiation) and "-active" (capable of causing an effect). The term emerged in the late 19th century following the discovery of radioactivity by scientists like Marie and Pierre Curie and Henri Becquerel. It originally described substances that emitted radiation.
The word gained prominence after the discovery of radium and polonium in 1898. Initially, it was used to describe the emission of radiation, and its usage expanded with the development of nuclear physics and applications in medicine and industry.
Memory tip
Think of a radio constantly emitting energy; a radioactive substance similarly emits particles/rays.
Word Origin
"Relating to or producing rays, and having the capacity to perform an action or process."