proton

noun

pro·​ton ˈprō-ˌtän 

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with the neutron is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673 × 10⁻²⁷ kilogram

protonic

prō-ˈtä-nik 

adjective

Examples of proton in a Sentence

Recent Examples on the Web

Within the first second, protons and neutrons formed. —The Editors, JSTOR Daily, 30 Jan. 2025

This occurred when the universe had expanded and cooled enough to allow electrons and protons to form the first neutral atoms of hydrogen. —Robert Lea, Space.com, 28 Jan. 2025

Isotopes are variants of a chemical element that have the same number of protons but different numbers of neutrons in their nuclei. —Jess Thomson, Newsweek, 5 Dec. 2024

The electric field is a way to describe interactions with electric charges (like electrons and protons), and the magnetic field describes what happens when those charges are moving (either in an atom or in an electric current). —Rhett Allain, WIRED, 24 Jan. 2025

Word History

Etymology

Greek prōton, neuter of prōtos first — more at proto-

First Known Use

1920, in the meaning defined above

Phrases Containing proton

• proton pump inhibitor
• proton synchrotron

Kids Definition

proton

noun

pro·​ton ˈprō-ˌtän 

: an atomic particle that occurs in the nucleus of every atom and carries a positive charge equal in size to the negative charge of an electron

protonic

prō-ˈtän-ik 

adjective

Medical Definition

proton

noun

pro·​ton ˈprō-ˌtän 

: an elementary particle that is identical with the nucleus of the hydrogen atom, that along with neutrons is a constituent of all other atomic nuclei, that carries a positive charge numerically equal to the charge of an electron, and that has a mass of 1.673×10⁻²⁴ gram

protonic

prō-ˈtän-ik 

adjective