Particle physics GapFill

Each particle has a corresponding antiparticle with equal mass but the particle and antiparticle equal and opposite quantum numbers (such as charge or spin).
For instance, the antiparticle of the proton is the antiproton, and the antiparticle of the electron is the  photonpositronbeta particleproton.
When a particle and its corresponding antiparticle meet, they will undergo  annihilationdecaypair productionparticle exchange.
A photon with sufficient energy can create a particle and antiparticle pair in a process known as  decaypair productionparticle exchangeannihilation.

There are four fundamental interactions through which particles can affect each other:

• Gravity, which interacts via the graviton (a theoretical particle)
• Electromagnetism, which interacts via  virtual photonsleptonselectronspions and is responsible for the phenomena surrounding electric charges
• The weak nuclear force, which interacts via  electronsW⁺ and W⁻ bosonsvirtual photonsleptons, and is responsible for particle interactions like  alpha decaypair productionbeta decayannihilation
• The strong nuclear force, which interacts via  electronsleptonsgluonsW⁺ and W⁻ bosons and is responsible for holding nuclei together

Particles are categorised as either hadrons (containing quarks) or leptons.
Hadrons containing three quarks are known as baryons. The  neutrinomuonneutronproton is the only stable baryon, which all baryons eventually decay into.
Hadrons containing a quark and an antiquark are known as mesons.  W⁺ bosonsNeutrinosProtonsKaons are mesons containing a strange quark, and can decay into pions.

Quarks come in different types such as up (u), down (d) and strange (s).
The quark make-up of the proton is  up anti-strangeup down downdown anti-upup up down, the quark make-up of the neutron is  up up downup down downdown anti-upup anti-strange, the quark make-up of a positive pion is  up down downup anti-downdown anti-upup anti-strange.
Leptons do not contain any quarks, and are fundamental particles.  KaonsNeutrinosMuonsPions are charged leptons which can decay into electrons.
In particle interactions, baryon number, lepton number, strangeness, charge, energy and momentum all have to be conserved (they have to be the same before and after); however, in weak interactions  baryon numbermomentumstrangenessenergy can change by 0, +1 or -1.