Particles Flashcards
Nucleon number
Total number of protons and neutrons
What is an isotope?
Atoms with the same number of protons but different number of neutrons
What is Specific Charge?
The ratio of its charge to its mass given in coulombs per kilogram.
What is the strong nuclear force?
A force that holds protons and neutrons together to maintain a stable nucleus
• Can be an attractive at 3fm or a repulsive force less than 0.5 fm
• Has very short range 0.5 and 3fm
• Overcomes the repulsion between the protons
•Exchange particle pion
What is the electromagnetic force?
The force that controls interaction between charged particles.
• Has inifinte range
• Exchange particle is a photon
Beta minus decay
Neutron turns into a proton then releases an electron + antineutrino
Beta plus decay
Proton turns into a neutron then releases a positron
Neutrino
Subatomic particle whose existence was hypothesised to maintain the conservation pf energy in beta decay
Electron capture
Process in which a proton in a proton-rich nucleus turns into a neutron as a result of interacting through the weak interaction with an inner-shell electron
Electron volt
work done to accelerate an electron through a potential difference of 1V. 1eV is equal to the charge of an electron
Gauge Boson
The exchange particles that transmit the four fundamental interactions between particles
Weak nuclear force
A force that acts in the nucleus to change the quark type. Controls decays in the nucleus. Only acts over the distance of the nucleus
Alpha decay
The process of an unstable nucleus emitting an alpha particle (two protons and two neutrons) to become more stable.
What is a photon?
Packets (waves) of energy
Hadrons
Particles that interact through the strong interaction
Leptons
A group of elementary subatomic particles, consisting of electrons, muons and neutrinos
Annihilation
A particle and its antiparticle collide and get converted into energy. Energy is released into 2 photons to conserve momentum
Antiparticle
All particles have a corresponding particle with the same mass but opposite charge and conservation numbers
Baryon
A class of hadron, that’s made up of 3 quarks. Proton is the only stable baryon
Electron diffraction
Spreading of electrons as they pass through a gap similar to the magnitude of their de broglie wavelength. Evidence of wave-like properties of particles
Energy levels
Defined and distinct energies at which electrons can exist in an atom An electron can’t exist between energy levels
Excitation
The process of an electron taking in exactly the right quantity of energy to move to a higher energy level
Ground state
Most stable energy level an electron can exist in
Isotopic data
Data from isotopes that can be used for a purpose, such as carbon dating
Kaon
Meson that decays into pions
Lepton number
A quantum number that’s conserved in all particle interactions. Both electron lepton numbers and muon lepton numbers mist be conserved
Meson
A class of hadron that is made up of a quark and antiquark pair
Pair production
Process of sufficiently high-energy photon converting into a particle and its corresponding antiparticle. To conserve momentum, this usually occurs near a nucleus
Pion
A type of meson and the exchange particle for the strong nuclear force
Positron
A positively charged particle that is the antiparticle of an electron
Strange particles
Particles that are produced through the strong interaction but decays through the weak interaction
Strangeness
A quantum number that is conserved in strong interaction but not in weak interactions. This reflects that strange particles are always produced in pairs.
Threshold frequency
The minimums frequency of photons required for photoelectrons to be emitted from the surface of a metal plate through the photoelectric effect. It’s equal to the metal’s work function divided by Planck’s constant.
