Fermions
We think of matter as being made up from three main particles 鈥 protons, neutrons and electrons.
However the full set of matter particles is the fermions. This has a much greater variety of sub-atomic particles. Some of these rarely exist outside of particle accelerators or major astronomical events, such as the Big Bang or supernovae.
Electrons are one of the six types of lepton. Leptons are particles that can exist on their own.
Protons and neutrons belong to the 鈥榝amily鈥 of hadrons.
The hadrons are the heavier particles. All hadrons are made of quarks (which can only exist when bound together with other quarks). Hadrons fall into two types:
- baryons - Made up of three quarks. Protons and neutrons are both types of baryon
- mesons - Made up of a quark and antiquark pair
There are six types of quarks. These give hadrons electrical charge and this is important in the process of beta decay.
The make-up and charge of the main sub-atomic particles can be explained by what they are made of.
Proton
Proton: Two up quarks, one down quark.
Charge \(=2 \times \left(+\frac{2}{3}\right) - \frac{1}{3}\)
\(= +\frac{4}{3}-\frac{1}{3}\)
\(= + 1\)
Neutron
Neutron: Two down quarks, one up quark.
Charge \(=2 \times \left(-\frac{1}{3} \right)+\frac{2}{3}\)
\(=- \frac{2}{3}+ \frac{2}{3}\)
\(= 0\)
Electron
Charge \(=-1\)