Femtometer
A femtometer (fm) is a unit of length in the metric system, equal to one-quadrillionth of a meter (1 fm = 10⁻¹⁵ meters). It is also known as a fermi, named after the physicist Enrico Fermi. Femtometers are used to measure extremely small distances at the subatomic level, such as the size of protons, neutrons, and atomic nuclei. For example, the radius of a proton is about 0.84 femtometers. This unit is commonly used in nuclear physics and particle physics, but it's far too small for everyday measurements.
Bohr Radius
The Bohr radius is a fundamental physical constant that represents the average distance between the nucleus and the electron in a hydrogen atom in its ground state, according to the Bohr model of the atom.
Its value is approximately 5.29177 × 10⁻¹¹ meters (about 0.529 angstroms).
Named after physicist Niels Bohr, who introduced the model in 1913.
It sets a natural length scale in atomic physics and quantum mechanics.
Used to describe atomic sizes and electron orbitals.
Key facts:
Bohr radius ≈ 5.29 × 10⁻¹¹ m
Represents the typical size of a hydrogen atom’s electron orbit
Fundamental to quantum physics and atomic structure
The Bohr radius is essential for understanding atomic dimensions and quantum behavior of electrons.
No conversions available for length.