Three Charged Leptons
The electron, muon, and tau are three distinct charged leptons. Each has electric charge −1 elementary charge, but their masses differ greatly: the muon is about 207 times as massive as the electron, and the tau is about 17 times as massive as the muon. Each has a neutrino partner with zero electric charge, so the claim applies specifically to the charged particles, not all leptons.
AI-generated illustration; mass bars are schematic, not to linear scale.
