The production of x-radiation that occurs in an x-ray tube requires the movement of negatively charged particlestraveling from one side of the tube to the other. This movement of charges must occur in: A. Vaccuum. B. A tungsten gas environment. C. An aqueous medium. D. Any condition that exists inside the x-ray tube, including a nonvacuum.

Answer: A

Explanation: In order to generate X ray we need to strongly accelerate the electrons to do that it is necessary a vacuum tube. It applied a high voltage difference to obtain huge kinetic energy to the electrons before impacting to a catode in the other side. The strng electron colision produces a hard Xray radiation of bremsstrahlung. In the X ray spectrum there are also characteristic emission lines from each target. The target to impact the electrons can be tungsten, copper, molibdeno etc. In order to keep high speed of the electron before the colision to the target we need to conduct this process under vacuum conditions.