Where on the electromagnetic spectrum do ionizing rays fall?

Ionizing rays fall in the region of the electromagnetic spectrum that has wavelengths shorter than 390 nanometers (nm), specifically in the ultraviolet (UV) range and beyond. This range includes X-rays and gamma rays, which are known for their ability to ionize atoms by displacing electrons. This property of ionization means that they can cause chemical changes and damage to living tissues, which is why there are stringent safety protocols associated with their use.

The choice indicating 390nm or less accurately describes the area where ionizing radiation exists, as it aligns with the understanding that shorter wavelengths correspond to higher energy photons capable of ionization.