Radon is a naturally occurring radioactive gas that is colorless, odorless, and tasteless. It is classified as a noble gas, atomic number 86, and is chemically inert. Radon is formed through the radioactive decay of uranium, which is present in various types of soil, rocks, and water. It is typically found at low levels in the atmosphere but can accumulate in enclosed spaces such as homes and buildings. Exposure to high levels of radon gas over a prolonged period is associated with an increased risk of lung cancer. Radon is considered to be the second leading cause of lung cancer after smoking. The risk of developing lung cancer from radon exposure depends on factors such as the concentration of radon, the duration of exposure, and individual susceptibility. Testing for radon levels in homes and workplaces is important for identifying and mitigating potential health risks. Measures such as ventilation systems and sealing cracks in foundations can help reduce radon levels indoors. Public health authorities and regulatory agencies often provide guidelines and recommendations for radon testing and mitigation to minimize health risks associated with this radioactive gas.