physics particles

Electric field

Electric fields are regions in which a charge experiences a force. They exist around charged particles and plates. The direction and strength of the field be visualised by the drawing of field lines.

What is potential difference?

the work done in moving a unit charge between two points.

What is the work done moving a charge of 1C through a potential difference of 1V?

1J

What is an electronvolt?

An electronvolt (eV) is the amount of energy gained by an electron when accelerated through a potential difference of one volt.

How much energy is equivalent to one electronvolt in joules?

1 electronvolt is equivalent to 1.6 × 10−19 joules.

What is the formula that relates energy, charge, and potential difference?

The formula is E = QV, where E is energy, Q is charge, and V is potential difference.

Standard Model

The standard model is the collection of the fundamental particles that make up everything. There are several particles included in it.

Fermion

Fermions are matter particles, they consist of quarks and leptons.

Quark

There are 6 types (Up, Down, Charm, Strange, Top, Bottom). Each quark has a fraction of the magnitude charge of an electron.

Lepton

There are 6 types. The Electron, Muon, Tau each have a charge of -1. The Electron Neutrino, Muon Neutrino, Tau Neutrino each have a charge of 0.

Hadron

The word comes from Greek meaning heavy. These are particles made up of Quarks.

Baryon

Made up of 3 Quarks, e.g., the proton and the neutron.

Meson

Made of a Quark and Anti-Quark pair. Very short lifespan.

Boson

The Force mediating Particles, consists of Photons, W and Z bosons and gluons.

Particle accelerator

Collisions of particles inside particle accelerators is evidence for the existence of quarks.

Anti-particle

Will have the same magnitude of charge as the corresponding particle, however the sign will be opposite. E.g., an up quark has a charge of 2/3e and an anti-up quark has a charge of -2/3e.

Annihilation

This occurs when a particle comes into contact with its corresponding antiparticle. This produces energy which is evidence for antimatter.

Beta decay

To follow the conservation of energy a third particle must be released during the decay. This particle is the neutrino, and beta decay is used as evidence for the existence of the neutrino.

Photoelectric Effect

Photons incident on a metal can cause the metal to eject an electron. The photons must be of sufficient energy. This phenomenon is called photoemission and is evidence for the particle model of light.

Threshold Frequency

The minimum frequency to allow photoemission to occur.

Work Function

The minimum energy to allow photoemission to occur.