Angstrom
Definition and meaning of Angstrom in chemistry.
An Angstrom (Å) is a unit of length equal to one ten-billionth of a meter (10^-10 m), used to express extremely small distances such as atomic radii and wavelengths of light.
In more detail
The Angstrom is particularly valuable in chemistry and physics for measuring distances at the atomic and subatomic scale, where other metric units become impractically small. Named after Swedish physicist Anders Jonas Ångström, this unit is especially common in spectroscopy, where it describes wavelengths of electromagnetic radiation, and in crystallography, where it quantifies atomic spacing in crystal structures. Although the nanometer (nm) is now the preferred SI unit, with 1 Å = 0.1 nm, the Angstrom remains widely used in scientific literature and experimental data.
Key facts
| Symbol | Å (or A in plain text) |
|---|---|
| Conversion | 1 Å = 10⁻¹⁰ meters = 0.1 nanometers |
| Named after | Anders Jonas Ångström, Swedish physicist |
| Field | Physical Chemistry |
The diameter of a hydrogen atom is approximately 1 Å, making it an intuitive reference point for comparing atomic sizes.
Frequently asked questions
Why is the Angstrom still used if nanometers are the SI standard?
Scientists in spectroscopy, materials science, and crystallography continue using Angstroms because it provides convenient numerical values for atomic and molecular dimensions, distances that would require decimals in nanometers.
What is the symbol for Angstrom?
The symbol is Å (the Scandinavian letter A with a ring above it), sometimes abbreviated as A in plain text where special characters are unavailable.