Convert Bohr Radius (a₀) to Angstrom (Å) instantly.
About these units
Bohr Radius (a₀)
The Bohr radius, equal to approximately 5.29177 × 10⁻¹¹ meters, is the most probable distance between the electron and nucleus in the ground state of hydrogen according to the Bohr model. While modern quantum mechanics has evolved far beyond the Bohr model, the radius remains a remarkably accurate approximation for average atomic dimensions. The Bohr radius acts as a natural "yardstick" for the size of atoms and is frequently used in atomic physics and quantum chemistry. Many atomic properties — orbital sizes, electron probability distributions, and energy levels — are conveniently expressed in multiples of the Bohr radius. Because it reflects fundamental constants, including Planck's constant and the electron charge, the Bohr radius also appears in theoretical analyses of physical systems and helps unify atomic physics concepts across different contexts.
Angstrom (Å)
The ångström, equal to 10⁻¹⁰ meters, is traditionally used to measure atomic scales, bond lengths, and wavelengths of electromagnetic radiation, particularly in the X-ray and ultraviolet regions. Although not an SI unit, the ångström persists because it aligns conveniently with many natural atomic dimensions — hydrogen's typical bond lengths, for example, are close to 1 Å. Scientists in crystallography, astronomy, materials science, and spectroscopy routinely use ångströms when describing the spacing between atoms in a crystal lattice or the wavelength of certain spectral lines. The convenience comes from avoiding unwieldy decimals: instead of writing 0.154 nm, one may write 1.54 Å. While modern research increasingly prefers SI nanometers or picometers, the ångström remains deeply embedded in scientific traditions and continues to serve as a practical shorthand for atomic-scale measurements.