Convert Bohr Radius (a₀) to Pica (pica) 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.
Pica (pica)
A pica is another typographic unit, equal to 12 points, or 1/6 of an inch, making it larger and more suited to structural layout than to fine detail. Picas are commonly used to measure text blocks, column widths, margins, and line lengths in print and digital page design. The pica originated alongside the point in printing traditions stretching back to the 18th and 19th centuries. It offered a convenient intermediate scale—small enough for precise adjustments but large enough for practical page design. When newspapers became widespread, picas helped designers rapidly calculate column grids and organize dense printed pages. Even as publishing tools evolved into software like Adobe InDesign and LaTeX, picas remain deeply integrated into the workflow of book designers, typographers, and professional printers. They are part of a system that allows page elements to be arranged with precision, ensuring that every visual aspect of a document aligns harmoniously.