proton

[ proh-ton ]

/ ˈproʊ tɒn /

Save This Word!

noun Physics, Chemistry.

a positively charged elementary particle that is a fundamental constituent of all atomic nuclei. It is the lightest and most stable baryon, having a charge equal in magnitude to that of the electron, a spin of ½, and a mass of 1.673 × 10-27 kg. Symbol: P

QUIZ

CAN YOU ANSWER THESE COMMON GRAMMAR DEBATES?

There are grammar debates that never die; and the ones highlighted in the questions in this quiz are sure to rile everyone up once again. Do you know how to answer the questions that cause some of the greatest grammar debates?

Question 1 of 7

Which sentence is correct?

His boss, whom he admires, is waiting to meet with him about the big project.

His boss, who he admires, is waiting to meet with him about the big project.

TAKE THE QUIZ TO FIND OUT

Origin of proton

Term first suggested in 1920 by English physicist Ernest Rutherford as noun use of Greek prôton, neuter of prôtos “first,” the proton being the constituent of hydrogen nuclei, and formed on the analogy of electron; see first, electron

OTHER WORDS FROM proton

pro·ton·ic, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use proton in a sentence

The gravity is enough to squeeze atoms until electrons combine with protons to make neutrons.
The Weirdest Object in the Universe|Matthew R. Francis|May 18, 2014|DAILY BEAST
The nuclei of atoms are stable only when they contain certain numbers of neutrons and protons.
The Atomic Fingerprint|Bernard Keisch
Thus, while all sodium atoms contain 11 protons, only those sodium atoms that contain 12 neutrons are stable.
The Atomic Fingerprint|Bernard Keisch
The numbers denote the atomic weight of the atom, which is the total number of protons and neutrons in its nucleus.
The Atomic Fingerprint|Bernard Keisch

The size ratio of these particles to protons is somewhat like the ratio of an individual proton to a large star.
The Untouchable|Stephen A. Kallis
To have produced the complete alignment of both the protons and the electrons within a mass might have been attempted before.
Where I Wasn't Going|Walt Richmond

British Dictionary definitions for proton

proton

/ (ˈprəʊtɒn) /

noun

a stable, positively charged elementary particle, found in atomic nuclei in numbers equal to the atomic number of the element. It is a baryon with a charge of 1.602176462 × 10 –19 coulomb, a rest mass of 1.672 62159 × 10 –27 kilogram, and spin 1/2

Word Origin for proton

C20: from Greek prōtos first

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for proton

proton

[ prō′tŏn′ ]

A stable subatomic particle in the baryon family having a mass of 1.672 X 10-24 grams (1,836 times that of the electron) and a positive electric charge of approximately 1.602 X 10-19 coulombs. Protons make up part of the nucleus of all atoms except hydrogen, whose nucleus consists of a single proton. In neutral atoms, the number of protons is the same as the number of electrons. In positively charged atoms, the number of protons is greater than the number of electrons, and in negatively charged atoms electrons outnumber protons. Protons are believed to be composed of two up quarks and one down quark. See Table at subatomic particle.

Cultural definitions for proton

proton

[ (proh-ton) ]

An elementary particle with a positive charge, found in the nucleus of an atom.

notes for proton

A proton is over a thousand times heavier than an electron.

notes for proton

Protons and neutrons make up most of an atom's mass.