particle physics Flashcards
define alpha decay
the process of an unstable nucleus emitting an alpha particle to become more stable
define annihilation
the process of a particle and its antiparticle colliding and being converted into energy. the energy is released into two photons to conserve momentum
define antiparticle
corresponding antiparticle to a particle with same mass but opposite charge and conservation numbers
define baryon number
a quantum number that is conserved in all particle interactions.
define baryon
a type of hadron, made up of 3 quarks
what is the only stable baryon?
proton
define beta-minus decay
the process of a neutron inside a nucleus turning into a proton, and emitting a beta-minus particle (electron) and a neutrino
define beta-plus decay
the process of a proton inside a nucleus turning into a neutron and emitting a beta-plus particle (proton) and a neutrino.
define electron diffraction
the spreading of electrons as they pass through a gap similar to the magnitude of their wavelength. (de Broglie)
define electron - volt
the work done to accelerate an electron through a potential difference of 1V.
define energy levels
defined and distinct energies at which electrons can exist in an atom.
define excitation
the process of an electron taking in exactly the right quantity of energy to move to a higher energy level
define gauge boson
the exchange particles that transmit the four fundamental interactions between particles
define ground state
the lowest, most stable energy level that an electron can exist in
define hadrons
a class of subatomic particle that experiences the strong nuclear interaction
define ionisation
the process of an atom losing an orbital electron and becoming charged
define isotope
an atom of an element with the same number of protons but different numbers of neutrons
define isotopic data
data from isotopes that can be used for a purpose, such as carbon dating
define kaon
a type of meson that decays into pions
define lepton number
a quantum number that is conserved in all particle interactions. both electron lepton numbers and muon lepton numbers must be conserved
define lepton
a group of elementary subatomic particles, consisting of electrons, muons and neutrinos
define meson
a class of hadron that is made of a quark and antiquark pair
define muon
a type of lepton that decays into electrons
define neutrino
a subatomic particle whose existence was hypothesised to maintain the conservation of energy in beta decay
define nucleon number (A)
the sum of the number of protons and neutrons in a given nucleus
define nucleon
a proton or neutron
define pair production
the process of a high energy photon converting into a particle and its corresponding antiparticle.
define photon
a packet of energy
define pion
a type of meson and the exchange particle for the strong nuclear force
define positron
electron antiparticle
define proton number (Z)
the number of protons in a given nucleus
define stopping potential
the minimum potential difference required to stop the highest KE electrons from leaving the metal plate in the photoelectric effect
define strange particles
particles produced through the strong interaction that decay through the weak interaction
define strong nuclear force
a force that acts between nucleons in a nucleus to keep it stable
what is the range of the strong nuclear force
attractive at distances up to 3fm, repulsive under 0.5fm
define threshold frequency
the minimum frequency of photons required for photoelectrons to be emitted from the surface of a metal plate through the photoelectric effect
what is the threshold frequency equal to?
the metals work function divided by Planck’s constant
define work function
the minimum energy required to remove an electron from a metal’s surface
