Illinois Home Inspector Practice Exam

When radon undergoes radioactive decay, what type of radiation is emitted?

1. Beta particles

2. Gamma rays

3. Alpha particles

4. X-rays

The correct answer is: Alpha particles

Radon emits alpha particles during its radioactive decay process. Radon is a noble gas and a product of uranium decay, which means it undergoes a process known as alpha decay. In this phase of decay, the nucleus of the radon atom loses two protons and two neutrons, which are collectively known as an alpha particle. This type of radiation is relatively heavy and can be stopped by a sheet of paper or the outer layer of human skin, yet it can pose significant health risks if radon gas is inhaled, as it can damage lung tissue over time. Understanding this is crucial for home inspectors when assessing environmental health risks in properties, especially in areas known for high radon levels. The other forms of radiation mentioned, like beta particles and gamma rays, are different phenomena associated with other types of radioactive decay and not specifically with radon's decay process. Beta particles, for instance, are high-energy, high-speed electrons or positrons emitted during beta decay, while gamma rays are high-frequency electromagnetic radiation that typically accompanies both alpha and beta decay but is distinct from the emission of alpha particles. X-rays, on the other hand, are produced by electronic transitions in atoms and are not a product of radioactive decay at all.