Convert Centiinch (cin) to Bohr Radius (a₀) instantly.
About these units
Centiinch (cin)
A centiinch is 1/100 of an inch, making it a small but straightforward derivative of the imperial system. Although seldom used today, it historically appeared in precision engineering, machining, and scientific instruments that relied on extremely fine calibrations before widespread adoption of decimal-based units like millimeters. Because the inch was long established in many English-speaking industries, dividing it into 100 equal parts provided a convenient decimal alternative to the more cumbersome 1/8 or 1/16 subdivisions found in carpentry and early tooling. The centiinch never gained strong traction, particularly once the metric system became dominant for precision work. However, it remains an interesting footnote in the evolution of measurement, illustrating attempts to reconcile the decimal preference with traditional imperial standards.
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.