The Etymology of Proton
Ernest Rutherford named the proton in 1920, choosing the Greek neuter 'prōton' (first thing) because the hydrogen nucleus — a single proton — was believed to be the fundamental building block of all heavier nuclei. The root 'prōtos' (first) traces to Proto-Indo-European *per- (forward, first), one of the most productive roots in the Indo-European family. It gave Greek 'prōtos,' which produced 'protein' (the primary substance of life), 'prototype' (first model), 'protagonist' (first actor in a drama), and 'protocol' (originally the first sheet glued to a papyrus scroll). Rutherford considered alternative names including 'prouton' and the Victorian coinage 'protyle,' but 'proton' won for its classical elegance.