Convert Bohr Radius (a₀) to Vara Castellana (vara castellana) 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.
Vara Castellana (vara castellana)
The Vara Castellana is the traditional Castilian vara, approximately 0.8359 meters in length, and was widely used throughout Spain for centuries. Its application extended to construction, tailoring, agriculture, and property measurement, serving as a versatile unit bridging everyday tasks and formal documentation. The vara's influence reached Spain's colonies, where regional variations arose, adapting the unit to local measurement conventions. In architecture, artisans used the Vara Castellana to proportion buildings, plan streets, and ensure symmetry, making it central to civil and domestic design. Although no longer in practical use, the Vara Castellana remains crucial for historians, architects, and legal researchers examining pre-metric Spain and Latin America.