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noun Uncommon

proton

PROH-ton

Proton (noun) means a positively charged particle found in the nucleus of every atom. Example: “The number of protons in an atom determines which element it is.”

noun
1
A positively charged particle found in the nucleus of every atom.
"The number of protons in an atom determines which element it is."
"Protons and neutrons together make up most of an atom's mass."

How to use proton

Learner’s notes

In plain EnglishA tiny positively-charged particle inside an atom's nucleus, alongside neutrons.

Easily confused with
Common pairings
proton beam proton number

Word forms

protons plural

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Test yourself on “proton” A quick quiz — meaning, synonyms & usage

Fill the gap

Can you complete this real example?

The number of _____ in an atom determines which element it is.

Etymology

Coined in 1920 by physicist Ernest Rutherford from Greek prôton, "first thing," echoing the earlier-named electron.

Origin: Greek · First attested 1920

Class of 1920 proton joined the language around 1920.
See the full Class of 1920 →
p

Related words

Rhymes for proton

See all rhymes for proton →

Frequently asked questions

What does “proton” mean?

The word “proton” means a positively charged particle found in the nucleus of every atom. In plain terms, a tiny positively-charged particle inside an atom's nucleus, alongside neutrons.

How do you pronounce “proton”?

“Proton” is pronounced PROH-ton (/ˈpɹoʊ.tɑn/ in IPA).

How do you use “proton” in a sentence?

Here is “proton” used in a sentence: “The number of protons in an atom determines which element it is.”

What is another word for “proton”?

Words with a similar meaning to “proton” include p.

What part of speech is “proton”?

“Proton” is a noun.

Where does the word “proton” come from?

The word “proton” dates back to around 1920 and comes from Greek. Coined in 1920 by physicist Ernest Rutherford from Greek prôton, "first thing," echoing the earlier-named electron.

Is “proton” a common word?

“Proton” is an uncommon word in modern English.

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Definitions: FreeDict original editorial