What is the wavelength of an xray?

Answer 1

In general, X-rays have a wavelength of between 10 and 0.01 nanometers. That's between 10-8 and 10-11 meters. Remember that a shorter wavelength means a higher frequency, and, therefore, higher energy.

The frequency range of X-rays is 30 petahertz to 30 exahertz (30 x 1015 Hz to 30 x 1018 Hz) and they have energies in the 120 eV to 120 keV range. (An eV is an electron volt.)

Note that X-rays are of shorter wavelength than visible light, but not as short as gamma rays.

Answer 2

X-rays have a wavelength anywhere from 10 nm down to 0.01 nm.

Between 10 nm and 0.1 nm, they're called "soft" x-rays; below 0.1 nm, they're called "hard" x-rays. The x-rays used for medical diagnostic imaging are "hard" x-rays.