Which of the following is an example of ionizing radiation?

Ionizing radiation refers to radiation that has enough energy to remove tightly bound electrons from atoms, creating ions. Gamma rays are a type of ionizing radiation that falls within the electromagnetic spectrum and have high energy and short wavelengths. Because they can penetrate most materials and can affect living tissue, they pose a significant health risk, which is why understanding and managing exposure to gamma rays is critical in safety practices.

In contrast, other options such as microwaves, electromagnetic radiation (as a broader term that includes non-ionizing types), and lasers (which can also refer to various forms of light that are non-ionizing) do not have the energy necessary to ionize atoms. Hence, they do not qualify as ionizing radiation. Understanding the distinguishing characteristics of ionizing versus non-ionizing radiation is fundamental in safety and health contexts, especially in environments where radiation is present.