SYMBOL
Each particle has its own unique symbol. These symbols are used to distinguish different particles in diagrams and equations, such as the Feynman diagram below which illustrates the production of the Higgs boson.
The symbol equation below uses particle symbols to show how a muon decays into a pair of neutrinos and an electron (through the weak force, carried by a W boson).
𝝻 ➝ 𝗩𝝻 + 𝗩̅𝗲 + 𝗲
ELECTRIC CHARGE
Electric charge is the property of particles which causes them to experience a force under a magnetic field. It also governs electrostatic attraction - the phenomenon responsible for the formation of composite matter, such as atoms.
There are two types of electric charge: positive and negative. If two objects have the same type of charge, they will repel; whereas two objects with opposite charges will attract.
When two charged particles interact, they exchange a virtual photon (the carrier of the electromagnetic force). Therefore, electric charge is a measure of how particles interact with the electromagnetic field.
Every particle with an electric charge is surrounded by an electric field: a cloud of these virtual photons. This is what causes the interaction with other charged objects. The Feynman diagram below displays the repulsion between two electrons due to the exchange of a virtual photon.
Electric charge is a conserved quantity, meaning that its value never changes. It cannot be created or destroyed. Therefore, the reactants and products of a reaction always have the same net electric charge.
INTRINSIC ANGULAR MOMENTUM (SPIN)
Intrinsic angular momentum, sometimes called spin, is one out of two forms of angular momentum - the other being orbital angular momentum. Angular momentum refers to the momentum which an object has while it is stationary.
Orbital angular momentum is the momentum an object has while in orbit of another object. For example, the Earth has orbital angular momentum around the Sun due to gravity. Similarly, an electron has orbital angular momentum around an atomic nucleus due to electromagnetism.
The other form of angular momentum is intrinsic angular momentum. This can be imagined as the momentum an object has while it spins on its axis. However, the intrinsic angular momentum of a particle does not refer to its actual momentum. Rather, the spin refers to how many times the particle needs to be rotated in order to return to its original state.
For example, a particle with intrinsic angular momentum of 1 (a vector boson) will return to its original state after a 360º rotation. In this way, a particle with a spin value of 2 (a tensor boson) would return to its original state after only a 180º rotation. A particle with a spin of 0.5 (a fermion) needs to be rotated 720º before returning to its original state. Finally, a particle with a spin of 0 (a scalar boson) will not change its state at all under any rotation.
In composite particles (particles which contain multiple fundamental particles), the spin values of its components are added together to calculate the spin value of the whole particle.
In this diagram, object A has both intrinsic angular momentum about its axis, as well as orbital angular momentum around object B.
MASS
Mass is the measure of an object's resistance to acceleration when a force is applied. The greater an object's mass, the more force needed to accelerate it.
As Albert Einstein illustrated with his famous equation (E=mc²), mass can be converted into energy and vice versa. This is how the sun creates light and heat. Einstein also suggests that - in some sense - mass and energy can be considered to be the same thing. This is called mass-energy equivalence.
Some particles (the gluon and the photon) have no mass. This means that they have no resistance to acceleration and are able to travel at the fastest possible speed: 299,792,458 meters per second. This is commonly referred to as the speed of light - although, notably, not only light can travel this fast.