What is a characteristic of gamma rays?

Gamma rays are a form of electromagnetic radiation that are known for their very high frequency. This high frequency correlates to their energy, which is considerably greater than that of other forms of electromagnetic waves, such as radio waves and visible light.

In terms of the electromagnetic spectrum, as frequency increases, the energy of the photons increases as well. Gamma rays typically have frequencies greater than 10^19 Hz, placing them at the extreme end of the spectrum, making them far more energetic than X-rays or ultraviolet light. This high frequency is also why gamma rays can penetrate materials that are opaque to other forms of radiation.

The other characteristics listed do not apply to gamma rays: they do not have the longest wavelength—rather, they have the shortest wavelength in the electromagnetic spectrum; they do not travel the slowest, as all electromagnetic waves, including gamma rays, travel at the speed of light in a vacuum; and they are not visible to the human eye, as their wavelengths are much shorter than those of visible light.

Understanding these characteristics is essential in fields like medical imaging and radiation therapy, where gamma rays are utilized due to their unique properties.