Editing Radiation (section)

=== X-rays ===
{{Main|X-ray}}
X-rays are electromagnetic waves with a wavelength less than about 10<sup>−9</sup>&nbsp;m (greater than {{val|3|e=17|u=Hz}} and {{val|1,240|u=eV}}). A smaller wavelength corresponds to a higher energy according to the equation [[Energy|''E'']] = [[Planck constant|''h'']][[speed of light|''c'']]/[[wavelength|''λ'']]. (''E'' is Energy; ''h'' is the Planck constant; ''c'' is the speed of light; ''λ'' is wavelength.) When an X-ray photon collides with an atom, the atom may absorb the energy of the photon and boost an electron to a higher orbital level, or if the photon is extremely energetic, it may knock an electron from the atom altogether, causing the atom to ionize. Generally, larger atoms are more likely to absorb an X-ray photon since they have greater energy differences between orbital electrons. The soft tissue in the human body is composed of smaller atoms than the calcium atoms that make up bone, so there is a contrast in the absorption of X-rays. X-ray machines are specifically designed to take advantage of the absorption difference between bone and soft tissue, allowing physicians to examine structure in the human body.

X-rays are also totally absorbed by the thickness of the earth's atmosphere, resulting in the prevention of the X-ray output of the sun, smaller in quantity than that of UV but nonetheless powerful, from reaching the surface.