An angstrom, angström, or ångström (Å) is a non-SI unit of length equal to 10⁻¹⁰ metres, 0.1 nanometres or 100 picometres. Ã…, or Ã¥, is a letter, representing a vowel, in the Swedish, Finnish, Danish, Norwegian, Walloon and Chamorro alphabets. ... The International System of Units (abbreviated SI from the French phrase, Système International dUnités) is the most widely used system of units. ... The word unit means any of several things: Physical unit, a fundamental quantity of measurement in science or engineering Units (computer program), a popular program that does unit conversion. ... In general English usage, length (symbols: l, L) is but one particular instance of distance – an objects length is how long the object is – but in the physical sciences and engineering, the word length is in some contexts used synonymously with distance. Height is vertical distance; width (or breadth... The metre is the basic unit of length in the International System of Units (SI: Système International dUnités). ... A nanometre (American spelling: nanometer, symbol: nm) is 1. ... Picometre (American spelling: picometer) is an SI measure of length that is equal to 10−12 of a metre. ...

The angstrom is named after the Swedish physicist Anders Jonas Ångström, one of the founders of spectroscopy. It is often used for expressing the sizes of atoms, whose radii are between 0.25 and 3 Å, and the lengths of chemical bonds, which are typically between 1 and 2 Å. For a list of objects of size 1 to 10 Å, see 1 E-10 m. A physicist is a scientist trained in physics. ... Anders Jonas Ã…ngström Anders Jonas Ã…ngström (August 13, 1814 – June 21, 1874) was a physicist in Sweden, one of the founders of the science of spectroscopy. ... Spectroscopy is the study of spectra, that is, the dependence of physical quantities on frequency. ... Properties For alternative meanings see atom (disambiguation). ... A chemical bond is the phenomenon of atoms being held together in molecules or crystals. ... To help compare different orders of magnitude this page lists lengths between 100 pm and 1 nm (10-10 m and 10-9 m). ...

This is a non-SI unit, and therefore its use is officially discouraged. It is listed in Table 8 of the SI brochure ("Other non-SI units currently accepted for use with the International System"). BIPM explains "Table 8 lists some other non-SI units which are currently accepted for use with the SI to satisfy the needs of commercial, legal and specialized scientific interests. These units should be defined in relation to the SI in every document in which they are used. Their use is not encouraged." The International System of Units (abbreviated SI from the French phrase, Système International dUnités) is the most widely used system of units. ... The Bureau International des Poids et Mesures (International Bureau of Weights and Measures, or BIPM) is a standards organization, one of the three organizations established to maintain the SI system under the terms of the Metre Convention. ...

Nanometres or picometres can easily be used instead. However, despite its official deprecation, many scientists continue to use it. They claim it is a more convenient unit, corresponding more closely to the size of the items being discussed, e.g. atoms, grains of interstellar dust, optical wavelengths, etc. Interstellar cloud is the generic name given to accumulations of gas and dust in our galaxy. ... The wavelength is the distance between repeating units of a wave pattern. ...

For historical reasons, astronomers prefer to use the angstrom when working with visible-light spectra. An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... The optical spectrum (light or visible spectrum) is the portion of the electromagnetic spectrum that is visible to the human eye. ...

Note that the symbol for the ångström unit is always a capital Å and never italicised.

Unicode includes the "angstrom sign" at U+212B (in your browser it looks like Å). However, the "angstrom sign" is canonically decomposed into U+00C5, thereby seen as a (preexisting) encoding mistake, and it is better to use U+00C5 (Å) directly. In computing, Unicode provides an international standard which has the goal of providing the means to encode the text of every document people want to store on computers. ... A web browser is a software application that enables a user to display and interact with HTML documents hosted by web servers or held in a file system. ... In Unicode, canonical decomposition is a process of converting composite characters into canonically-ordered strings of simpler characters using Unicode canonical mappings. ...

See also

• Conversion of units