Icon class icon_class fas fa-quote-left icon_class_computed fas fa-quote-left Related content Protons are spin-1/2 fermions and are composed of three valence quarks, making them baryons A focus BDD for the AtomicNucleus block Source Wikipedia Copyright information Text from Wikipedia and Wiktionary web pages quoted for educational purposes is subject to the Wikipedia Creative Commons Attribution ShareAlike Licence Snippet kind INFO Previous snippet Full quote One or more protons are present in the nucleus of every atom; they are a necessary part of the nucleus. URL https://en.wikipedia.org/wiki/Proton Next snippet Related snippets A proton is a subatomic particle, symbol p or p+, with a positive electric charge of +1e elementary charge and a mass slightly less than that of a neutron. Protons and neutrons, each with masses of approximately one atomic mass unit, are collectively referred to as "nucleons" (particles present in atomic nuclei). Related snippets (backlinks) The number of protons in the nucleus is the defining property of an element, and is referred to as the atomic number (represented by the symbol Z). Since each element has a unique number of protons, each element has its own unique atomic number. Although protons were originally considered fundamental or elementary particles, in the modern Standard Model of particle physics, protons are classified as hadrons, like neutrons, the other nucleon. Protons are composite particles composed of three valence quarks: two up quarks of charge + 2/3e and one down quark of charge –1/3e. The rest masses of quarks contribute only about 1% of a proton's mass. The remainder of a proton's mass is due to quantum chromodynamics binding energy, which includes the kinetic energy of the quarks and the energy of the gluon fields that bind the quarks together. Visit also Visit also (backlinks) Flags