Ångström
An ångström (symbol: Å) is a unit of length commonly used in physics, chemistry, and biology to measure very small distances, such as atomic and molecular scales. It is equal to 10⁻¹⁰ meters, or 0.1 nanometers (nm).
The unit is named after the Swedish physicist Anders Jonas Ångström, who made significant contributions to spectroscopy.
Key facts:
1 ångström = 10⁻¹⁰ meters = 0.1 nanometers
Used to measure atomic and molecular sizes, wavelengths of light, and crystal lattice constants
Common in fields like crystallography, chemistry, and materials science
Though largely replaced by the nanometer in the SI system, the ångström remains widely used in scientific literature to describe very small lengths.
Fermi
A fermi is a unit of length used in nuclear physics to measure extremely small distances, such as the size of atomic nuclei. It is equal to 1 femtometer (fm), which is 10⁻¹⁵ meters.
The unit is named after the Italian physicist Enrico Fermi, known for his work in nuclear physics.
Key facts:
1 fermi = 1 femtometer = 10⁻¹⁵ meters
Used to measure nuclear dimensions and particle sizes
Essential in the study of nuclear and particle physics
The fermi is vital for describing distances at the subatomic scale, much smaller than atoms and molecules.