X-Rays are a form of ionizing radiation, meaning as the rays pass through matter in sufficient quantity, they disrupt the molecular orbit of electrons to form ions, a process that expends the energy of the x-ray while the ions formed break off from the molecules and collide with more electrons, which creates more ions.
In humans and animals, this process can become an uncontrolled chain reaction with excessive or continued exposure, so nuclear medicine personnel must be shielded from radiation exposure, or face catastrophic health consequences.
