Qué (quién) es X-rays - definición
![photoabsorption]], as well as a leveling off at higher photon energies due to [[Compton scattering]]. The attenuation length is about four orders of magnitude longer for hard X-rays (right half) compared to soft X-rays (left half).](https://commons.wikimedia.org/wiki/Special:FilePath/Attenuation.svg?width=200 "photoabsorption]], as well as a leveling off at higher photon energies due to [[Compton scattering]]. The attenuation length is about four orders of magnitude longer for hard X-rays (right half) compared to soft X-rays (left half).")
![Abdominal radiograph]] of a pregnant woman, a procedure that should be performed only after proper assessment of benefit versus risk](https://commons.wikimedia.org/wiki/Special:FilePath/BabyXray.png?width=200 "Abdominal radiograph]] of a pregnant woman, a procedure that should be performed only after proper assessment of benefit versus risk")
![CT scan]] ([[transverse plane]]) slice – a modern application of [[medical radiography]]](https://commons.wikimedia.org/wiki/Special:FilePath/Brain CT scan.jpg?width=200 "CT scan]] ([[transverse plane]]) slice – a modern application of [[medical radiography]]")
![Example of a [[Crookes tube]], a type of [[discharge tube]] that emitted X-rays](https://commons.wikimedia.org/wiki/Special:FilePath/Crookes' type discharge tubes Wellcome M0015832EA.jpg?width=200 "Example of a [[Crookes tube]], a type of [[discharge tube]] that emitted X-rays")
![Taking an X-ray image with early [[Crookes tube]] apparatus, late 1800s. The Crookes tube is visible in center. The standing man is viewing his hand with a [[fluoroscope]] screen. The seated man is taking a [[radiograph]] of his hand by placing it on a [[photographic plate]]. No precautions against radiation exposure are taken; its hazards were not known at the time.](https://commons.wikimedia.org/wiki/Special:FilePath/Crookes tube xray experiment.jpg?width=200 "Taking an X-ray image with early [[Crookes tube]] apparatus, late 1800s. The Crookes tube is visible in center. The standing man is viewing his hand with a [[fluoroscope]] screen. The seated man is taking a [[radiograph]] of his hand by placing it on a [[photographic plate]]. No precautions against radiation exposure are taken; its hazards were not known at the time.")
![radiation exposure]] during the X-ray procedure would be negligible.](https://commons.wikimedia.org/wiki/Special:FilePath/Historical X-ray nci-vol-1893-300.jpg?width=200 "radiation exposure]] during the X-ray procedure would be negligible.")
![Images by James Green, from "Sciagraphs of British Batrachians and Reptiles" (1897), featuring (from left) ''Rana esculenta'' (now ''[[Pelophylax lessonae]]''), ''Lacerta vivipara'' (now ''[[Zootoca vivipara]]''), and ''[[Lacerta agilis]]''](https://commons.wikimedia.org/wiki/Special:FilePath/James Green & James H. Gardiner - Sciagraphs of British Batrachians and Reptiles - 1897 - Ycba f6c56349-13da-4efc-a671-e40af53b0823.jpg?width=200 "Images by James Green, from \"Sciagraphs of British Batrachians and Reptiles\" (1897), featuring (from left) ''Rana esculenta'' (now ''[[Pelophylax lessonae]]''), ''Lacerta vivipara'' (now ''[[Zootoca vivipara]]''), and ''[[Lacerta agilis]]''")
![A [[chest radiograph]] of a female patient, demonstrating a [[hiatal hernia]]](https://commons.wikimedia.org/wiki/Special:FilePath/Radiografía pulmones Francisca Lorca.cropped.jpg?width=200 "A [[chest radiograph]] of a female patient, demonstrating a [[hiatal hernia]]")
![characteristic K lines]] for rhodium atoms.](https://commons.wikimedia.org/wiki/Special:FilePath/TubeSpectrum.jpg?width=200 "characteristic K lines]] for rhodium atoms.")
![[[Wilhelm Röntgen]]](https://commons.wikimedia.org/wiki/Special:FilePath/WilhelmRöntgen.JPG?width=200 "[[Wilhelm Röntgen]]")
![X-ray fine art photography of [[needlefish]] by [[Peter Dazeley]]](https://commons.wikimedia.org/wiki/Special:FilePath/X-RayOfNeedlefish-1.jpg?width=200 "X-ray fine art photography of [[needlefish]] by [[Peter Dazeley]]")
![1896 plaque published in ''"Nouvelle Iconographie de la Salpetrière"'', a medical journal. In the left a hand deformity, in the right same hand seen using [[radiography]]. The authors named the technique Röntgen photography.](https://commons.wikimedia.org/wiki/Special:FilePath/X-ray 1896 nouvelle iconographie de salpetriere.jpg?width=200 "1896 plaque published in ''\"Nouvelle Iconographie de la Salpetrière\"'', a medical journal. In the left a hand deformity, in the right same hand seen using [[radiography]]. The authors named the technique Röntgen photography.")
![UV light]]. Different applications use different parts of the X-ray spectrum.](https://commons.wikimedia.org/wiki/Special:FilePath/X-ray applications.svg?width=200 "UV light]]. Different applications use different parts of the X-ray spectrum.")
Wikipedia
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers 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 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it X-radiation to signify an unknown type of radiation. Spellings of X-ray(s) in English include the variants x-ray(s), xray(s), and X ray(s).
X-rays are also used in ways such as checking for broken bones, detecting certain kinds of diseases, "identification of some metals", and ascertaining the locations of weak points in steel.
