What does Atom mean?

The word ##"atom"## derives from the Greek, ##alphatauomuos##, which means ##"indivisible"## or ##"uncuttable"##.

Some of the early Greek philosophers (circa 6th/5th century BC) proposed that the ##"atom"## was the smallest unit of matter. This probably derived more from philosophical notions than from experiment, and today we know that atoms are composed of protons, neutrons, and electrons.