protonlar

Protonlar, known in English as protons, are positively charged baryons that form a large portion of atomic nuclei. As one of the two main types of nucleons—the other being neutrons—protons combine with neutrons to give each element its atomic number and many of its chemical properties.

Composition and properties: Each proton is made of three valence quarks (two up quarks and one down quark) bound by gluons. It has a rest mass of about 938 MeV/c^2, electric charge +e, and spin 1/2. Its size is typically described by a charge radius of roughly 0.84–0.87 femtometers. The proton’s magnetic moment arises from its internal quark structure.

Role in matter: The number of protons in a nucleus determines the element’s identity (its atomic number Z). Protons experience electromagnetic repulsion, which is offset by the strong nuclear force binding nucleons in the nucleus. Protons are produced in stars and participate in most chemical and nuclear processes on Earth.

Internal structure and experiments: The proton’s quark–gluon structure is described by quantum chromodynamics. Deep inelastic scattering experiments reveal partons inside the proton and provide measurements of form factors and parton distribution functions, informing models of charge and magnetization distributions.

Stability: The proton is currently regarded as stable within the Standard Model, though many theories beyond it predict rare proton decay. Experimental searches place lower bounds on the proton lifetime well beyond 10^34 years.