Question: what is meant by the wavelength of uv light

title: Ultraviolet
text: Ultraviolet ( UV ) is electromagnetic radiation with a wavelength from 10 nm to 400 nm , shorter than that of visible light but longer than X-rays . UV radiation is present in sunlight constituting about 10 % of the total light output of the Sun . It is also produced by electric arcs and specialized lights , such as mercury - vapor lamps , tanning lamps , and black lights . Although long - wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms , it can cause chemical reactions and causes many substances to glow or fluoresce . Consequently , the chemical and biological effects of UV are greater than simple heating effects , and many practical applications of UV radiation derive from its interactions with organic molecules . 

Answer: answer: Ultraviolet ( UV ) is electromagnetic radiation with a wavelength from 10 nm to 400 nm , shorter than that of visible light but longer than X-rays . Although long - wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionize atoms , it can cause chemical reactions and causes many substances to glow or fluoresce .