Year 12 - Particles Flashcards
Annihilation
A corresponding particle and anti-particle (E.g. Electron and Positron) collide and annihilate each other. The mass is converted into energy in the form of two photons. Electric Charge, Baryon Number, Lepton Number, and Momentum are all conserved.
Anti-Particle
Every particle has a corresponding Anti-Particle.
Similarity: Same (rest) mass or rest energy (1)
Difference: Opposite quantum states E.g. Charge, Baryon Number, Lepton Number (1)
Baryon
A Hadron, composed of 3 Quarks. Note: Anti-Baryon would be 3 Anti-quarks.
Baryon Number
A quantum number identifying that a particle is a Baryon E.g. B=+1. Baryon Number is always conserved during an interaction.
Beta Minus Decay
A (Free) Neutron (udd) changes into a Proton (uud) via the weak interaction (W- Boson) and emits a Beta Minus Particle and an Anti-neutrino.
Beta Plus Decay
A (Free) Proton (uud) changes into a Neutron (udd) via the weak interaction (W+ Boson)and emits a Beta Plus Particle (Positron) and a Neutrino.
Charge
Charge, Q, isa physical quantity, which can be either positive or negative. A charged particle will experience an EM Force.
Distribution of kinetic energies of β- particles
Existence of Neutrino. Beta particles have a range of (kinetic) energies. There is a fixed/maximum/total amount of energy (released) so there must be another particle that carries the energy differences/missing energy away.
Down Quark
1) Charge: -1/3
2) Baryon Number: +1/3
3) Strangeness Number: 0
Electron
A fundamental particle with a charge of -1e and Electron Lepton Number of +1.
Electron Capture
(Inner) orbiting electron [or electron surrounding the nucleus] captured by a proton (in the nucleus) converted into a neutron via the weak interaction (W+ Boson).
Electron Diffraction
The diffraction of electrons as they pass through a gap similar to the magnitude of their de Broglie wavelength. It is evidence of the wave-like properties of particles.
EM Force
The force of attraction or repulsion between two particles/bodies that have charge. The exchange particle for the EM Force is the Virtual Photon.
Exchange Particle
Theexchange particleis also known as a virtualparticle. It only exists for a very brief moment and its only role is to carry the force between theparticles. Exchange particles transfer Momentum.
Fundamental Particle
A particle that has no subatomic constituent parts.
Gauge Boson
Force carrying particles that carry the fundamental forces.
Gravitational Force
The force of attraction between two particles/bodies that have mass. The exchange particle for Gravity is the Graviton.
Hadron
Experience the Strong Force and composed of Quarks.
Ion
An atom that has either gained or lost electrons.
Isotope
Atoms with the same number of Protons and a different number of Neutrons.
Lepton
Leptons are fundamental particles which interact with all the fundamental forces except for the strong nuclear force.
Lepton Number
A quantum number identifying that a particle is a Lepton E.g. L=+1. Lepton Number is always conserved. Lepton number can additionally be divided into sub-categories, to show where it is an Electron or Muon.
Mass
Mass, m, isa physical quantity. A particle or body with mass will experience a Gravitational Force.
Meson
Hadron, composed of a Quark, Anti-quark Pair.
Muon
Leptons which are heavier versions of the Electron. They decay into Electrons. A fundamental particle with a charge of -1e and Muon Lepton Number of +1
Negative Kaon
1) Composition: Strange, Anti-Up
2) Charge: -1
3) Baryon Number: 0
4) Strangeness: -1
Negative Pion
1) Composition: Down, Anti-Up
2) Charge: -1
3) Baryon Number: 0
Neutral Kaon
1) Composition: Down, Anti-Strange
2) Charge: 0
3) Baryon Number: 0
4) Strangeness: +1
Neutral Pion
1) Composition: Up, Anti-up or Down, Anti-Down
2) Charge: 0
3) Baryon Number: 0
Neutrino
A subatomic particle whose existence was hypothesised to maintain the conservation of energy/mass in beta decay. They have negligible mass. They also have different flavours E.g. Electron Neutrino, Muon Neutrino.
Neutron
1) Composition: udd
2) Charge: 0
3) Baryon Number: +1
Nucleon
The collective term for protons and neutrons E.g. Sub-atomic particles that are in the nucleus.
Nucleon Number (A)
The number of nucleons in the nucleus E.g. Protons + Neutrons.
Pair Production
A photon interacts with orbital electron/nucleus in order to conserve momentum, energy of photon used to create corresponding particle anti-particle pair (E.g. Electron and Positron). Charge, Baryon Number, Lepton Number, and Momentum are all conserved.
Particulate nature of electrons
Charged particle moving in a Magnetic Field or Particle Collisions.
Particulate nature of light
Photoelectric effect.
Positive Kaon
1) Composition: Up, Anti-Strange
2) Charge: +1
3) Baryon Number: 0
4) Strangeness: +1
Positive Pion
1) Composition: Up, Anti-Down
2) Charge: +1
3) Baryon Number: 0
Positron
Positively charged particle that is the antiparticle of an electron. The Electron is the only particle to have an anti-particle with its own name.
Proton
1) Composition: uud
2) Charge: +1
3) Baryon Number: +1
Proton Number (Z)
The number of protons in the nucleus of an Atom. E.g. A Lithium nucleus contains 3 protons.
Quarks
Fundamental Particle that can combine to form Baryons and Mesons.
Specific Charge
Charge to Mass Ratio (Ckg-1)
Strange Quark
1) Charge: -1/3
2) Baryon Number: +1/3
3) Strangeness Number: -1
Strangeness
Strangeness occurs if a particle has a strange quark. Strangeness is conserved in strong interactions; but not in weak interactions.
Strong Nuclear Force (Interaction)
The force between Quarks/Hadrons. It isresponsible for keeping nucleus together. The strongforceonly acts over a range of 3fm. Between the distance of 3fm and 0.5fm separation the force is attractive. Below 0.5fm separation the force is repulsive.
Up Quark
1) Charge: +2/3
2) Baryon Number: +1/3
3) Strangeness Number: 0
Wave nature of electrons
Electron diffraction.
Wave nature of light
Interference e.g. Single/Double Slit Experiment
Weak Interaction
The weak interaction is responsible for the decay of atoms; The exchange particles that carry this force are the W– and W+ Bosons.
