How it got named
On 28 December 1895, Wilhelm C Röntgen presented his paper 'Über eine neue Art von Strahlen' ('On a New Kind of Rays') to the Würzburg Physical Medical Society [1]. These rays had been labelled with the letter 'x' to represent their unknown nature, which is understandable at a time when there was no knowledge of this strange radiation, and the nature and characteristics of radiation in general were not understood. The knowledge we have gained about x-rays belies the name, as we now possess extensive information about all aspects of x-rays.
What are X-rays?
X-rays are a form of radiation or electromagnetic wave, as are radio waves and visible light. Electromagnetic waves are variations in the amplitude of energy in time and are classified according to the speed with which they fluctuate over time. This defines the concept of the wavelength, the time taken by a wave to complete a full sequence. As a wave oscillates faster its wavelength becomes smaller and its frequency increases. More specifically, all electromagnetic waves lie in the electromagnetic spectrum, which is arranged by the wavelength or its equivalent, the frequency. X-rays lie above ultraviolet radiation, visible light and radio waves in the spectrum, and below cosmic radiation; they are a form of high energy radiation, with a high frequency and short wavelength.
Beyond the UV region of the electromagnetic spectrum lies the X-Ray region . We are familiar with X-Rays because of its medical applications. It covers wavelengths from about 10^-8m down to 10^-13(10^-4nm). One common way to generate X-Rays is to bombard a metal target by high energy electrons. X-Rays are used as a diagnostic tool in medicine and as a treatment for certain forms of cancer . Because X-Rays damage or destroy living tissues and organisms , care must be taken to avoid unnecessary or over exposure.