DANB Radiation Health and Safety (RHS) Practice Exam

X-rays are categorized in the electromagnetic spectrum according to their wavelengths. The electromagnetic spectrum is a range of all types of electromagnetic radiation, which includes visible light, radio waves, infrared radiation, ultraviolet rays, X-rays, and gamma rays. Each type of electromagnetic radiation is defined by its wavelength, which is the distance between successive peaks of the wave.

X-rays have much shorter wavelengths compared to visible light, usually ranging from about 0.01 to 10 nanometers. This short wavelength is responsible for their ability to penetrate various materials, including human tissue, which makes them useful for medical imaging.

The other options—milliliters, seconds, and liters—do not relate to the categorization of X-rays within the electromagnetic spectrum as they measure volume and time, respectively. Understanding the significance of wavelengths helps in grasping how X-rays function and their applications in medical and scientific fields.