What term describes the radioactivity that is around us from natural sources?

• A. Background radiation
• B. Ionising radiation
• C. Ultraviolet radiation
• D. Microwave radiation

Answer: (A)

There is a constant level of radioactive material and cosmic rays around us from natural sources, creating ambient radioactivity. This everyday exposure is called background radiation. It comes from things like rocks and soil containing trace radioactive elements, radon gas in the air, and cosmic rays reaching Earth. It represents the baseline amount of ionising radiation that everyone is exposed to, even without any artificial sources.

Ultraviolet and microwave radiation are different parts of the electromagnetic spectrum and are not described as background radioactivity. Ionising radiation describes the property of high-energy radiation that can remove electrons, but background radiation specifically refers to the ambient level of that radiation in our environment.