proton

Also known as p, ¹H⁺, 1H+, p⁺

A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 e (elementary charge). Its mass is slightly less than the mass of a neutron and approximately times the mass of an electron (the proton-to-electron mass ratio). Protons and neutrons, each with a mass of approximately one dalton, are jointly referred to as nucleons (particles present in atomic nuclei).

OverviewAI-generated

The proton, identified by the chemical formula H+, is a particle with a positive electric charge of 1. It was discovered in 1920. The particle has a spin quantum number of 0.5 and a parity quantum number of 1. Its isospin quantum number is 0.5, with an isospin z-component of 0.5.

The mass of the proton is 938.27208943, and its weight is 1.0078250319. It possesses a magnetic moment of 2.79284734463 and a g-factor of 5.5856946893. The particle has one hydrogen bond donor and zero hydrogen bond acceptors. Its topological polar surface area is 0, and its xlogP value is 0. Under pressure, the value is 100000000000000000000000000000000000.

Synthesized by Vinony from 26 facts across 4 sources: Wikidata, PubChem, PubMed, Vinony graph. Generated from structured data (not the Wikipedia text) and checked against those facts — may still contain errors.

Key facts

Particle.classification: Baryon
Particle.name: Proton
Particle.image: Quark structure proton.svg
Particle.caption: The valence quark content of a proton. The color assignment of individual quarks is arbitrary, but all three colors must be present. Forces between quarks are mediated by gluons.
Particle.composition: 2 up quarks (u), 1 down quark (d)
Particle.statistics: Fermionic
Particle.group: Hadron
Particle.interaction: Gravity, electromagnetic, weak, strong
Particle.antiparticle: Antiproton
Particle.theorized: William Prout (1815)
Particle.discovered: Observed as H+ by Eugen Goldstein (1886). Identified in other nuclei (and named) by Ernest Rutherford (1917–1920).
Particle.symbol: , , ,
Particle.mean_lifetime: > (stable)
Particle.electric_dipole_moment: <
Particle.spin:  ħ
Particle.parity: +1
Particle.condensed_symmetries: I(JP) = (+)

via Wikipedia infobox

Chemical data

Formula: H+
Molecular weight: 1.0078250319 g/mol
IUPAC name: proton
SMILES: [1H+]
InChIKey: GPRLSGONYQIRFK-FTGQXOHASA-N
XLogP: 0
Polar surface area: 0 Å²
H-bond donors: 1
H-bond acceptors: 0
Formal charge: 1

via PubChem

Research

218,771 papers

Proton Transfer Mechanisms in Bimetallic Hydrogenases.Accounts of chemical research · 2021Tai H, Hirota S, Stripp STDOI: 10.1021/acs.accounts.0c00651
Proton transfer pathway in anion channelrhodopsin-1.eLife · 2021Tsujimura M, Kojima K, Kawanishi S et al.DOI: 10.7554/eLife.72264
Proton-detected solid-state NMR spectroscopy at aliphatic sites: application to crystalline systems.ReviewAccounts of chemical research · 2013Asami S, Reif BDOI: 10.1021/ar400063y
The Protonic Brain: Nanoscale pH Dynamics, Proton Wires, and Acid-Base Information Coding in Neural Tissue.ReviewInternational journal of molecular sciences · 2026Grigorean VT, Tataru CI, Pantu C et al.DOI: 10.3390/ijms27020560
Linkage between proton binding and folding in RNA: implications for RNA catalysis.ReviewBiochemical Society transactions · 2005Bevilacqua PC, Brown TS, Chadalavada D et al.DOI: 10.1042/BST0330466
Halide-selective, proton-coupled anion transport by phenylthiosemicarbazones.Biochimica et biophysica acta. Biomembranes · 2022Howe ENW, Chang VT, Wu X et al.DOI: 10.1016/j.bbamem.2021.183828
Proton Control of Transitions in an Amino Acid Transporter.Biophysical journal · 2019Wu Z, Alibay I, Newstead S et al.DOI: 10.1016/j.bpj.2019.07.056
Proton transfer events in GFP.Physical chemistry chemical physics : PCCP · 2011Di Donato M, van Wilderen LJ, Van Stokkum IH et al.DOI: 10.1039/c1cp20387h

via PubMed

~23 min read

Encyclopedic overview

19 sections

Contents

Description
History
Occurrence
Stability
Quarks and the mass of a proton
Charge radius
Pressure inside the proton
Charge radius in solvated proton, hydronium
Interaction of free protons with ordinary matter
Proton in chemistry
Atomic number
Hydrogen ion
Proton nuclear magnetic resonance (NMR)
Human exposure
Antiproton
See also
References
Further reading
External links

One or more protons are present in the nucleus of every atom. They provide the attractive electrostatic central force which binds the atomic electrons. 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 is identified by the number of protons in its nucleus, each element has its own atomic number, which determines the number of atomic electrons and consequently the identity and chemical characteristics of the element.

Excerpted from Wikipedia’s “proton” article, available under the CC BY-SA 4.0 licence.