Convert Nanometer (nm) to Bohr Radius (a₀) instantly.
About these units
Nanometer (nm)
A nanometer—one billionth of a meter (10⁻⁹ m)—is central to nanoscience, nanotechnology, and molecular biology. Many structures essential to life fall into this scale: DNA's double helix is about 2 nm wide, viruses often measure tens to hundreds of nanometers, and key cell structures like ribosomes are on the order of 20–30 nm. In engineering, nanometers define the dimensions of modern semiconductor technology. Silicon transistors have shrunk to features only a few nanometers wide, approaching the physical limits of electron behavior in solid-state materials. In optics, wavelengths of ultraviolet light can be expressed in nanometers, as can surface roughness, material grain sizes, and thin-film coatings. The nanometer is ubiquitous across modern science because it describes both biological and technological structures at the frontier of research.
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.