Radon-222 is a colorless, odorless, and tasteless radioactive gas that occurs naturally from the decay of uranium found in soil, rock, and water. It is part of the noble gas family and has a half-life of about 3.8 days, which means it decays relatively quickly compared to other radioactive elements. When radon-222 accumulates in enclosed spaces, such as homes and buildings, it can pose health risks, particularly lung cancer. Testing for radon levels is important, especially in areas with high uranium content, to ensure safe indoor air quality and minimize exposure to this hazardous gas.