Topic 8-Nuclear and Particle physics

What are three constituents of an atom?

Protons neutrons electrons

What is the proton number and how is it denoted?

The number of protons in an atom, denoted by (Z)

What is the nucleon number-‘d how is it denoted?

Number of protons and neutrons in an atom, denoted by (A)

What did Rutherford’s alpha particle scattering experiment demonstrate?

The existence of small, dense, positively charged nucleus at the centre of the atom

Key observations of Rutherford’s experiment?

Most passed right through the thin gold, some were deflected at large angles, very few reflected straight back

What is thermionic emission?

The emission of electrons from a heated metal surface

How do electron guns accelerate electrons?

Using a potential difference to accelerate electrons released from the cathode towards the anode

What are 2 types of particle accelerators?

Linear accelerators (LINAC) and cyclotrons

How does a cyclotron accelerate particles?

Using a magnetic field and an alternating electric field to accelerate particles in a spiral path

What is the formulae for the radius of the path of a charged particle in a magnetic field?

r = mv/BQ

What properties must be conserved in particle interactions?

Momentum, charge, energy (mass/energy equivalence)

What is pair production?

The conservation of a photon into an equal amount of matter and antimatter

What is annihilation in particle physics?

The process where a particle and its antiparticle collide and their masses are converted into energy

What is the electron volt (eV) used to measure?

Small amounts of energy, specifically the kinetic energy of an electron accelerated across a potential difference of 1V

What is the time dilation and how does it affect particle lifetimes?

Time dilation is the phenomenon where time runs at different speeds depending on the observers motion, causing particles moving at relativistic speeds to have a longer lifetimes as observed by a stationary observer

What are hadrons and how are they classified?

Hadrons are particles that experience the strong nuclear force and are made of quarks. They are classified into baryons, antibaryons and mesons

What is the standard quark-lepton model?

A model that classifies all particles as hadrons, leptons or photons, with hadrons being made of quarks and lepton being fundamental particles

What is the significance of the top quark in the standard model?

The top quark was predicted by the symmetry of the standard model and was discovered through experiments, confirming the model’s predictions

What must be conserved to in a particle interaction for it to be possible?

Charge, baryon number and lepton number

What is de Brodie wavelength formula?

(λ = h/p) (λ=wavelength),(h=Plancks constant),(p=momentum of particle). p=mv

What is the mass/energy equivalence formula?

E = mc² (E=energy)(m=mass)(c=speed of light in a vacuum)

what is the unit of energy commonly used in particle physics?

Electron volt (eV) megaelectron volt (MeV) gigaelectron volt (GeV)

What is the process of beta-minus decay?

A neutron decays into a proton, electron and an electron antineutrino

What is a bubble chamber used for?

To observe the paths of charged particles by detecting the ionized particles they leave behind in a superheated liquid

What is the significance of muon decay in demonstrating time dilation?

Muons travel at relativistic speeds and their observed lifetimes are longer than expected, providing evidence for time dilation