What is a characteristic of gamma rays?

Gamma rays are a form of electromagnetic radiation that are characterized by their high energy. This high energy allows them to penetrate various materials, including clothing and human tissue. Unlike lower-energy forms of radiation, gamma rays do not get absorbed easily and can pass through many substances with ease. This property makes them particularly significant in both medical and industrial applications, where their penetrating ability can be advantageous, such as in cancer treatment and radiography.

The other options do not accurately describe the nature of gamma rays. For example, low energy and easy absorption do not apply, as this would refer to lower energy radiation types. While gamma rays are indeed used in some diagnostic imaging, their primary association is with therapeutic applications rather than routine imaging like X-rays. Additionally, although excessive exposure to gamma rays can indeed be harmful, the statement implying they are only harmful at extremely high doses underestimates the risks associated with even lower exposures, making it an incomplete characterization. Thus, the defining characteristic of gamma rays lies in their high energy and ability to penetrate materials effectively.