Basic particle knowledge

• Electrons

  • have relative charge of -1 or -1.6x10^-19
  • mass of 9.11x10^-31
• Protons:

  • have charge of 1.6x10^19
  • have mass 1.67x10^-27
• Nucleon number is total no. of protons and neutrons in the nucleus.
• Isotopes are atoms that have the same number of protons but different number of neutrons.
• specific charge is the charge of the particle over mass of the particle
• the specific charge of ions uses the net charge over the total mass instead of regular charge.
• The strong nuclear force is one of the four fundamental forces of nature and provides an attractive force between nucleons with a range of 3fm.
• At ranges below 1fm the strong nuclear force is repulsive to prevent the collapse of the atom. from 1-3 fm the strong nuclear force is attractive ,overcoming electrostatic force, prevents protons being repulsive.
• Alpha radiation usually occurs in very large nuclei. An alpha particle consists of 2 protons plus 2 neutrons. After decay proton number decreases by 2 , nucleon number decreases by 4.
• Beta radiation occurs with nuclei that have too many neutrons , beta particles exist of fast moving electrons. In a nucleus a neutron decays and an electron anti-neutrino.
• Neutrinos are particles of zero mass and are extremely small mass.
• Gamma radiations is a type of electromagnetic radiation that is emitted by unstable nuclei. it often occurs straight after alpha or beta decay.
• Wave theory says that light is electromagnetic radiation, the radiation consists of two linked electric and magnetic field waves.
• Einstein observed through photoelectric effect that radiation was usually emitted as bursts of very energies. he believed that these observations fit light as a particle and not a wave.
• Photon energy , E=hf
• E=mc^2 is the equation to find the energy stored in mass.
• Annihilation is when a particle and its corresponding anti-particle meet together , all their mass and kinetic energy is converted into two photon of equal frequency that move off in opposite directions.
• Pair production is the opposite of annihilation , the energy of one photon can be used to create a particle and its corresponding antiparticle. any remaining energy becomes kinetic energy.
• The weak nuclear force is responsible for all decay , and has a exchange particle which are W bosons.
• Beta-minus decay is where a neutron decays into a proton and a W- boson, this then becomes a beta-minus particle and an anti-neutrino.
• Beta-plus decay is where a proton decays into a neutron and W+ boson. this then becomes a beta-plus particle and a neutrino.
• electron capture can only occur in proton rich nucleus , one of the excess protons interacts with the inner shell electrons to form a neutron and a neutrino.