GCSE Design and Technology Revision : Some Key Words

GCSE Design and Technology Revision: Impact on Sustainability

GCSE History Revision : American (Plains) Indians : Beliefs

A-Level Physics Revision : Leptons

  • Leptons are a group of elementary particles
  • Leptons interact with other particles via the weak, gravitational or electromagnetic interactions
  • Examples of leptons are:
    • The electron, e
    • The electron neutrino, νe
    • The muon, μ
    • The muon neutrino, νμ

      They are much lighter than Baryons and Mesons and are not subject to the strong interaction.

      There are six leptons in total, three of them are charged and three are uncharged.

      The charged particles are electrons, muons and tauons.
      The muon and tauon are similar to the electron but bigger.
      The muon is about 200 times bigger than the electron and the tauon is 3500 times bigger .

      Each of the charged leptons has its own neutrino. If a decay involves a neutrino and a muon, it will be a muon neutrino, not a tauon neutrino or electron neutrino.

      The neutrino is a chargeless, almost massless particle. It is NOT affected by the strong interaction or the EM force and hardly at all by gravity. It is extremely difficult to detect.

A-Level Physics Revision : Hadrons

Hadrons are not fundamental particles they are all made from smaller particles, quarks. The properties of a hadron are due to the combined properties of the quarks that it is made from. There are two categories of Hadrons: Baryons and Mesons


Examples are neutrons and protons . These are made from three quarks.


These are made from a quark and an antiquark. Examples are Pion Plus, Pion Zero, Kaon Plus and Kaon Zero.