X-rays are a form of high-energy electromagnetic radiation with shorter wavelengths than visible light and ultraviolet. These rays have the ability to penetrate materials that are opaque to normal light, making them essential in various applications; they are generated by energetic electron transitions or radioactive decay.
They are mainly used for medical purposes (e.g. X-rays), in chemical analysis with XRF spectrophotometry and in the analysis of the structure of materials with X-ray crystallography and X-ray absorption spectroscopy.
X-rays of very high energies are used in tumour therapy and radiosurgery allowing non-invasive precision surgery.
