Q. What are leptons? Give examples.

Leptons:

Leptons are lighter particles having mass equal to or less than about 207 times the mass of an electron except neutrino and antineutrino.

This group contains particles such like positron, electron, neutrino and antineutrino and positive and negative muons. The electron as well as positron is the antiparticles.

Neutrinos as well as antineutrino are also associated with β-ray emission. The neutrinos as well as antineutrinos are mass-less and charge-less particles but carrier of energy and spin. Muons were discovered in the cosmic ray studies.