Particles Flashcards
Describe the plum pudding model
A spherical cloud of positive charge with tiny electrons embedded in it
What is an isotope?
An isotope of an element had the same number of protons but a different number of neutrons
Describe the strong nuclear force
Has a very short range (attractive from 0.5fm-3fm), is repulsive when separation is 0.5fm, its exchange particles are gluons and pions
Describe the electrostatic force
has a very long range, obeys the inverse square law, is repulsive between two like particles, exchange partical is a virtual photon
Define random
Impossible to predict when or which nucleus will decay
Describe spontaneous
decay cannot be induced or influenced by external factors
What is an antiparticle
An antiparticle has the same rest mass/ energy but the opposite charge to its corresponding particle
What is annihilation?
Annihilation occurs when a particle and a corresponding antiparticle meet. Their mass is converted to radiation energy and two photons are produced in the process
What is pair production?
When a single photon interacts with the nucleus of an atom, it’s energy may be converted into a particle-antiparticle pair.
What are hadrons?
Particles made up of quarks, therefore subject to strong and weak interaction. the two subclasses of hadrons are baryons (3 quarks) and mesons (2 quarks)
What is a pion?
The exchange particle of the strong interaction between protons and neutrons in a nucleus
What is a lepton?
A fundamental particle that is subject to the weak force, but not the strong force.
Describe the decay of a muon
muon decays into a muon neutrino, an electron and anti electron neutrino is also created
Describe kaon pair production
Occurs via the strong interaction, where strangeness is conserved e.g. a high energy collision of two photons
Describe the decay of kaons
Kaons are unstable and decay via the weak interaction - strangeness is not conserved but cannot change by a value greater than one.
