Category: Education/Sciencegt; Its frequency range is 5×106~7.5×1014Hz.

The natural ultraviolet rays on Earth come from sunlight.

The main characteristic of ultraviolet rays is their strong chemical effects. It is easy to sensitize photographic films. In addition, ultraviolet rays have strong physiological effects and can sterilize. Ultraviolet rays can make fluorescent substances glow. The fluorescent effect of ultraviolet rays can be used for anti-counterfeiting. For example, the ultraviolet rays emitted by a banknote detector can make the fluorescent substances on banknotes glow (it can also make the fluorescent substances on anti-counterfeiting labels shine). In addition to using this kind of UV rays on banknote detectors, In addition to the effect, different materials can emit fluorescence of different colors under ultraviolet irradiation, which can be used to identify ancient paintings and take photos with ultraviolet light.