The Standard Model

Quarks
There are six quark flavours, split into three generations, each containing a +2/3 e and -1/3 e charged quark.

Generation I
The first generation contains the up and down quarks. These are the lightest and most stable of the quarks and do not decay. The existence of quarks was first suggested in 1961 and the first evidence of the existence of up and down quarks was found in 1968 at the Stanford Linear AcceleratorCentre.

Generation II
Charm and strange quarks make up the second generation of the standard model. Their masses are much larger than that of the up and down quarks so they are unstable. The existence of the strange quark was proven in 1968 along with the up and down quark. The charm quark was not even suggested until 1970 and evidence of it was first found in 1974 with the discovery of the J/ψ meson.

Generation III
The top and bottom quarks, found in the third generation are the heaviest and therefore most unstable. The existence of the third generation quarks was proposed in 1973 and the bottom quark was subsequently proven to exist in 1977. The top quark however was not definitively proven to exist until 1995 as it was initially predicted to have a much lower mass.

Electron, Muon and Tau
These particles all share the same charge (-1.6x10-19 C) but have increasing masses going up the generations. The electron is the lightest and therefore most stable and as such is the most common. Muons have a mass approximately 200x that of an electron and decay rapidly. Taus are heavier again and decay almost instantly.

Neutrinos
Neutrinos have no charge and are the lightest particle in each generation and are so light they were originally believed to have no mass. Their only effect on particle interactions is lepton number and they are produced in interactions such as beta decay:

n → p + e + ve

Anti-Particles
Each particle in the standard model has a corresponding anti-particle with the same mass and opposing charge. For neutrinos there is therefore no difference between the neutrino and the anti-neutrino so the only effect they have on particle interactions is conserving lepton number.

Hadrons
A Hadron is any composite particle that consists of a combination of quarks and antiquarks, including baryons and mesons.

Baryons
A Baryon is any particle that is made up of exactly three quarks.

Mesons
A Mesons is any particle that is made up of one quark and one antiquark.

Pions
Pions are a group of mesons made up of only up, down, anti-up and anti-down quarks. There are four possible combinations:

Kaons
Kaons are a group of mesons made up of one up, down, anti-up and anti-down quarks as well as one strange or anti-strange quark. There are four possible combinations: