Radioactive (adjective)

1. Having an unstable atomic nucleus which emit radiation as a means of becoming more stable.
2. Emitting radiation as a result of having an unstable atomic nucleus.
3. Relating to, or exhibiting, radioactivity.

Origin:

The word "radioactive" is derived from the word "radioactivity" which was first used in 1896 by french chemist and physicist, marie curie. it was used to describe the property of certain elements to emit energy in the form of waves or particles. the term radioactive is used to describe things that have an unstable atomic nucleus which emit radiation as a means of becoming more stable.

Examples:

1. The radioactive material was stored in a special container.
2. The area around the nuclear power plant was contaminated with radioactive materials.
3. The rock was radioactive, and emitted a dangerous level of radiation.
4. Radioactive isotopes are used in medical imaging.
5. The scientists were wearing protective gear to protect themselves from the radioactive particles.