Matter and radiation

• Charge of a proton in coulombs 


  +1.6x10^-19
• Mass of a proton in kilograms


  1.67x10^-27
• Mass of a neutron in kilograms 


  1.67x10^-27
• Charge of an electron in coulombs


  -1.6x10^-19
• Mass of an electron in kilograms 


  9.11x10^-31
• Proton number


  The number of protons in the nucleus of an atom

  Also known as the atomic number

  Atoms of the same atomic number are the same element
• Nucleon number


  The number of nucleons (protons+neutrons) in the nucleus of an atom

  Also known as the mass number
• Isotopes


  Atoms with the same number of protons but a different number of neutrons
• Specific charge


  The charge of the nuclide Q divided by the mass of the nuclide m. Or charge per unit mass of the nuclide

  S.c=Q/M

  Measured in ckg^-1
• nuclide 


  A type of nucleus with a particular number of protons and neutrons
• Strong nuclear force


  A force that acts between nucleons in a nucleus to keep it stable . It is attractive at distances of up to 3 fm and repulsive at separations of less than 0.5 fm
• Alpha decay

  The process of an unstable nucleus emitting an alpha particle (two protons and two neutrons) to become more stable

  mass number decreases by 4

  atomic number decreases by 2
• beta-Minus decay

  the process of a neutron inside a nucleus turning into a proton and emitting a beta-minus particle (an electron) and an antineutrino

  mass number stays the same

  atomic number increases by 1
• Beta plus decay


  The process of a proton inside a nucleus turning into a neutron and emitting a beta-plus particle (a positron) and a neutrino

  Mass number stays the same

  Atomic number decreases by 1
• Gamma radiation

  High energy photons emitted by unstable nuclei or produced in particle annihilations
• Neutrino


  A subatomic particle whose existence was hypothesised to maintain the the conservation of energy in beta decay
• Photon

  A packet of energy
• Antimatter 


  All particles have a corresponding antiparticle with the same mass but opposite charge and conservation numbers
• Rest mass


  Mass of an object at rest, m0
• Rest energy


  Energy due to rest mass

  (E=m0xc^2)
• Annihilation 


  The process of a particle and its antiparticle colliding and being converted into energy. the energy is released in two photons to conserve momentum.
• Pair production


  The process of a sufficiently high-energy photon converting into a particle and its corresponding antiparticle. to conserve momentum, this usually occurs near a nucleus
• Virtual particle 


  A particle that only exists for a short amount of time, it cannot be detected.
• Exchange particle

  A virtual particle that which allows forces to act in a particle interaction. exchange particles meadiate or carry a force.
• Virtual photon 


  The virtual particle which meadiates the electromagnetic forces
• Feynman diagram 


  A diagram used to represent particle interaction
• Electron-volt (eV)


  The work done to accelerate an electron through potential difference of 1V. 1eV is equal to the charge of an electron (E=qv).
• Gauge boson 


  The exchange particles that transmit the four fundamental interactions between particles.