X-ray scan of human hand. (Source: © PhotoEdit / stock.adobe.com)

High-energy short-wave electromagnetic radiation capable of penetrating most objects, e.g., the human body. The wavelength of X-rays is between 10 nm and 100 pm. This radiation is typically produced by the acceleration or deceleration of charged particles. Highly excited atoms can also emit X-rays. Due to its high penetrating ability, it is often used in medicine to visualize structures inside the human body or in industry to inspect welds. Because X-rays are ionizing radiation, they can affect living tissue. Precisely targeted, intense X-rays are used for cancer therapy.