ABSTRACT
A unit of length frequently used to describe the wavelength of light. It is named after the Swedish physicist Anders Jonas Ångström (1814–74), a founder of spectroscopy. It is equal to 10−10 meters (i.e. one ten thousand millionth of a meter) and is denoted by the symbol Å. Most of the visible spectrum lies in the wavelength range 3900 to 7500 Å.
