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Angstrom — Wikipedia (en)

Source: Wikipedia (en)
Original: https://en.wikipedia.org/wiki/Angstrom
License (as archived): CC-BY-SA-4.0
Archived: 2026-11-09T07:43:22.670Z
SHA-256 of the archived text: 365eda961fbaada4d5eb8c6bde06d7b3162794c2ec6e9a7722c91c87e9799e0b
Stable URL of this page: https://metraipolis.com/documento/dc_6a10bec142fa

How to cite

Angstrom — Wikipedia (en) — Wikipedia (en), https://en.wikipedia.org/wiki/Angstrom (CC-BY-SA-4.0); archived copy: https://metraipolis.com/documento/dc_6a10bec142fa (Metraipolis archive dc_6a10bec142fa, sha256 365eda961fbaada4d5eb8c6bde06d7b3162794c2ec6e9a7722c91c87e9799e0b)

BibTeX

@misc{dc6a10bec142fa,
  title = {Angstrom — Wikipedia (en)},
  howpublished = {Wikipedia (en)},
  url = {https://en.wikipedia.org/wiki/Angstrom},
  note = {License CC-BY-SA-4.0; archived copy https://metraipolis.com/documento/dc_6a10bec142fa; sha256 365eda961fbaada4d5eb8c6bde06d7b3162794c2ec6e9a7722c91c87e9799e0b},
  year = {2026}
}

Archived text

Reproduced under CC-BY-SA-4.0. Attribution: Wikipedia (en), https://en.wikipedia.org/wiki/Angstrom. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

The angstrom ( ANG-strəm, ONG-) is a unit of length equal to 10−10 m; that is, one ten-billionth of a metre, a hundred-millionth of a centimetre, 0.1 nanometre, or 100 picometres. The unit is named after the Swedish physicist Anders Jonas Ångström (1814–1874). It was originally spelled with Swedish letters, as Ångström and later as ångström. The unit's symbol is Å, which is a letter of the Swedish alphabet, regardless of how the unit is spelled. However, "A" or "A.U." (not to be confused with an astronomical unit, which has the same initials and therefore abbreviation) may be used in less formal contexts or typographically limited media. The angstrom is often used in the natural sciences and technology to express sizes of atoms, molecules, microscopic biological structures, and lengths of chemical bonds, arrangement of atoms in crystals, wavelengths of electromagnetic radiation, and dimensions of integrated circuit parts. The atomic (covalent) radii of phosphorus, sulfur, and chlorine are about 1 angstrom, while that of hydrogen is about 0.5 angstroms. Visible light has wavelengths in the range of 4000–7000 Å. In the late 19th century, spectroscopists adopted 10−10 of a metre as a convenient unit to express the wavelengths of characteristic spectral lines (monochromatic components of the emission spectrum) of chemical elements. However, they soon realized that the definition of the metre at the time, based on a material artifact, was not accurate enough for their work. So, around 1907 they defined their own unit of length, which they called "Ångström", based on the wavelength of a specific spectral line. It was only in 1960, when the metre was redefined in the same way, that the angstrom became again equal to 10−10 metre. Yet the angstrom was never part of the SI system of units, and has been increasingly replaced by the nanometre (10−9 m) or picometre (10−12 m).

Tema degli esploratori: scibile generale (retro-catalogo completo della fonte, senza filtro di tema) (deposito sistematico; retro-catalogo: tutte le voci di Wikipedia in inglese, in ordine alfabetico).
Fonte: Wikipedia in inglese, voce «Angstrom» — https://en.wikipedia.org/wiki/Angstrom
Wikidata Q81454: «unità di lunghezza» (dati Wikidata in CC0 1.0) — https://www.wikidata.org/wiki/Q81454
Autori: i contributori di Wikipedia (cronologia: https://en.wikipedia.org/wiki/Angstrom?action=history).
Licenza: Creative Commons Attribuzione-Condividi allo stesso modo 4.0 (CC BY-SA 4.0) — https://creativecommons.org/licenses/by-sa/4.0/. Il riuso richiede attribuzione e stessa licenza.
Estratto dell'introduzione non modificato nel contenuto; revisione 1379702038, consultata il 2026-11-09T07:37:37.214Z tramite l'API ufficiale di Wikipedia. Impronta SHA-256 dell'estratto: 9561a469951509f372e4cbc438555ab929a4e2e51da20cfcf90faf3cc6acfc21