u and d quarks (2 quarks)
and electrons and electron-type neutrinos (2 leptons)
along with their antiparticles. Each of these 4
particles have a 1/2 spin. Each pair differ in
charge by on unit: -1 and 0, and +2/3 and -1/3
muons and muon neutrinos
(another 2 leptons), and mesons and baryons (another 2
quarks) where strangeness and charm are new
properties. Once again, the particles come in
pairs and differ by one unit in charge.
At even higher energies, we
have found tau and its neutrino (2 leptons), and top
and bottom (2 quarks).
Carriers
The strong force is carried
between quarks by the gluon which binds quarks
together.
The photon is the carrier of
the electromagnetic force
Weak bosons are
the carriers of the weak force
Electromagnetism
and the weak interaction were unified in 1967 as
the electroweak force.