Proton

How to spell proton

6 letters · 2 syllables

How to pronounce proton

Say the part in capitals loudest.

What does proton mean?

1. nounA stable subatomic particle carrying a positive electric charge, found in the nucleus of every atom.

Proton in a sentence

• Each proton in the nucleus carries a positive electric charge.

• A hydrogen atom has a single proton at its centre.

Where does proton come from?

Language of origin: Greek

The word proton comes from the Greek protos, meaning 'first'. The same root gives us 'prototype' (the first model of something) and 'protagonist' (the first or leading actor). When the physicist Ernest Rutherford named the positively charged particle of the atomic nucleus in 1920, he chose this root deliberately to mark it as the most fundamental or first unit of positive charge, then attached the suffix -on that was becoming standard for naming elementary particles, as in 'electron' and later 'neutron'. The spelling stays close to its Greek source, with a single 't' and an 'o' before the 'n', which is exactly how it sounds. Because it is a modern scientific coinage rather than a word worn down by centuries of use, there is little in the spelling to trip up a writer.

How the word is built

• prot- (from Greek protos: first)
• -on (suffix for elementary particles)