proton
noun/ˈprəʊtɒn/
/ˈprəʊtɑːn/
(physics)- a very small piece of matter (= a substance) with a positive electric charge that forms part of the nucleus (= central part) of an atom see also electron, neutronTopics Physics and chemistryc2Word Origin1920s: from Greek, neuter of prōtos ‘first’.
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proton