Explain background radiation, identify an alpha particle and its charge, and list two uses of radioactive substances.

Here are the answers to the questions:

a) Background radiation is the ionizing radiation that is always present in the environment from natural sources (like cosmic rays, rocks, soil, and radon gas) and artificial sources (like medical procedures and nuclear fallout).

b) A particle emitted by a radioactive substance has two protons and two neutrons.
i) Name the particle emitted. * Alpha particle ii) What is the charge of the emitted particle? * +2 (since it has two protons, each with a charge of +1)

c) State two uses of radioactive substances. 1. Medical tracers (e.g., to diagnose diseases or image organs). 2. Smoke detectors (using alpha emitters to ionize air). (Other acceptable answers include: cancer treatment, sterilizing medical equipment, carbon dating, thickness gauges in industry, nuclear power generation.)