Chemistry

X-ray
From Wikipedia, the free encyclopedia
This article is about the form of radiation. For the method of imaging, see Radiography. For imaging in a medical context, see Radiology. For other uses, see X-ray (disambiguation).( a+b)
Not to be confused with X-wave.

Type equation here.

X-rays are part of the electromagnetic spectrum
X-radiation (composed of X-rays) is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz (3×1016 Hz to 3×1019 Hz) and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma rays. In many languages, X-radiation is called Röntgen radiation, after Wilhelm Conrad Röntgen, who is usually credited as its discoverer, and who had named it X-radiation to signify an unknown type of radiation.[1] Recently uncovered archival evidence shows that the original discoverer of X-rays was a Ukrainian physicist Ivan Pulyui, who worked in Vienna together with Röntgen and shared the results of his work with him.[2] Correct spelling of X-ray(s) in the English language includes the variants x-ray(s) and X ray(s).[3] XRAY is used as the phonetic pronunciation for the letter x.
X-rays from about 0.12 to 12 keV (10 to 0.10 nm wavelength) are classified as "soft" X-rays, and from about 12 to 120 keV (0.10 to 0.01 nm wavelength) as "hard" X-rays, due to their penetrating abilities.[4]
Hard X-rays can penetrate solid objects, and their most common use is to take images of the inside of objects in diagnostic radiography and crystallography. As a result, the term X-ray is metonymically used to refer to a radiographic image produced using this method, in addition to the method itself. By contrast, soft X-rays hardly penetrate matter at all; the attenuation length of 600 eV (~2 nm) X-rays in water is less than 1 micrometer.[5]
The distinction between X-rays and gamma rays has changed in recent... [continues]

Read full essay