Chemicals and Drugs

Protons

Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.

National Library of MedicineMedical Subject Headings2026

Structured Summary

Abstract

Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.

Chemical Identity

Chemical Information

Molecular Formula
H+
Molecular Weight
1.0078250319 g/mol
CAS Registry No.
12586-59-3
IUPAC Name
proton
InChIKey
GPRLSGONYQIRFK-FTGQXOHASA-N
SMILES
[1H+]
MeSH Unique ID
D011522
Source
PubChem CID 5460653

MeSH Record

Classification

Broader headings

Related Concepts

Knowledge Graph

Loading graph…

Drag nodes to rearrange; hover to trace links; click a node to open its page.

MeSH Record

Synonyms

5 entry terms
  • Hydrogen Ions
  • Hydrogen Ion
  • Ion, Hydrogen
  • Ions, Hydrogen
  • Proton

MeSH Record

Aspects Covered

3 allowable subheadings

Indexed with the subheadings adverse effects, classification, history.

MeSH Record

History Note

66

MeSH Hierarchy

Tree Numbers

  1. D01w.248w.497w.300w.459.700w
  2. D01w.268w.406w.750w
  3. D01w.362w.340w.750w
  4. G01w.249w.660w.500w

AMA Style

References

  1. National Library of Medicine. Protons. Medical Subject Headings (MeSH). 2026. Unique ID D011522. http://id.nlm.nih.gov/mesh/2026/D011522
  2. Protons. In: Wikipedia. https://en.wikipedia.org/wiki/Proton
  3. Protons. In: Wikidata. https://www.wikidata.org/wiki/Q2294
  4. Protons. In: PubChem Compound. CID 5460653. https://pubchem.ncbi.nlm.nih.gov/compound/5460653