DANB Radiation Health and Safety (RHS) Exam 2025 – 400 Free Practice Questions to Pass the Test

Gamma radiation has the highest penetration power among the types of radiation listed. This is due to its nature as a form of electromagnetic radiation, similar to X-rays but with a much higher energy level. Gamma rays have no mass and no charge, allowing them to penetrate matter more effectively than particulate radiation such as alpha and beta particles.

Alpha radiation, which consists of heavy helium nuclei, has the lowest penetration power and can be stopped by a sheet of paper or even the outer layer of human skin. Beta radiation, made up of electrons or positrons, has a moderate penetration capability, capable of penetrating through paper but can be halted by materials like plastic or glass.

X-ray radiation falls between beta and gamma radiation in terms of penetration power but does not reach the levels of gamma radiation. As a result, gamma radiation is particularly dangerous and requires dense materials, such as lead or several centimeters of concrete, to effectively shield against it. This property makes gamma radiation significant in both medical applications and considerations for radiation safety.