Convert Stone (US) (st (US)) to Proton Mass (mₕ (p)) instantly.
About these units
Stone (US) (st (US))
The US stone was an informal and nonstandardized unit occasionally used in the 19th century, with no single agreed-upon value. Unlike the British stone (14 pounds), the US stone varied regionally and by trade context, typically ranging from 12 to 16 pounds, depending on the commodity and location. Farmers, butchers, and merchants sometimes used stones to weigh produce, meat, or livestock, but the lack of uniform regulation prevented it from becoming an official or widely adopted unit. Today, the US stone is entirely obsolete, but references to it appear in historical American trade documents, agricultural records, and pre-standardization weight systems. It serves as a reminder of the diversity of early American measurements before the widespread adoption of the avoirdupois pound.
Proton Mass (mₕ (p))
The proton mass, approximately 1.67262192369 × 10⁻²⁷ kilograms, is central to chemistry, nuclear physics, and cosmology. Protons, along with neutrons, form the nuclei of atoms and therefore compose most of the mass of ordinary matter. The proton mass arises from the strong nuclear force and the dynamics of quarks and gluons within quantum chromodynamics (QCD). Interestingly, most of the proton's mass is not from its constituent quarks but from the energy stored in the strong force. Understanding the proton mass helps scientists explore nuclear stability, binding energies, and stellar nucleosynthesis—the processes that form elements inside stars.