The Ångström (symbol: Å) is a unit of measurement used to express very small lengths, particularly in the fields of physics and chemistry. It is equal to 10^-10 meters, or 0.1 nanometers. This unit is commonly used to measure atomic and molecular dimensions, such as the size of atoms and the wavelengths of light. The term is named after the Swedish physicist Anders Jonas Ångström, who made significant contributions to the study of spectroscopy in the 19th century. The Ångström is particularly useful in fields like nanotechnology and materials science, where precise measurements at the atomic level are essential.