Complex sentence: Electrons belong to the first generation of the lepton particle family, and are generally thought to be an elementary particle because it has no known components or substructure and has a mass that is approximately 1/1836 that of the proton.
Split into simpler sentences: Electrons belong to the first generation of the lepton particle family, and are generally thought to be an elementary particle because it has no known components or substructure. The electron has a mass that is approximately 1/1836 that of the proton.