Matter and Radiation

Matter and Radiation

1. α

   • Occurs with very large nuclei
   • Consists of 2 protons plus 2 neutrons
     • After Decay
       • Proton number decreases by two
       • Nucleon number decreases by 4

2. β-

   • Occurs with nuclei that have too many neutrons
   • Consists of a fast moving electron
   • In the nucleus, a neutron decays into a proton and an electron
     • The electron is emitted as the beta particle
     • An anti neutrino is also emitted
     • After decay
       • Proton number increases by 1
       • Nucleon number does not change

3. γ

   • Electromatic radiation emitted from an unstable nucleus
   • Gamma radiation often occurs straight after alpha or beta decay
     • The child nuclide formed often has excess energy which is released by gamma emission
   • No change occurs to either the proton or nucleon numbers as a result of gamma decay

4. ν

   • Emitted with β+ (beta plus) decay
     • β- decay results in the emission of an antineutrino
     • β+ decay, however, produces a neutrino
   • Are very difficult to detect as they have nearly zero mass and no charge
     • They also barely interact with matter
   • Billions of these particles (emitted from the sun) pass through our bodies every second (earth has hardly any effect on them)

5. Photons

   • Electromagnetic radiation is emitted as a short burst of waves
     • Each burst leaves the source in a different direction
     • Each burst is called a Photon
       • Each photon contains a set amount of energy
         • Proportional to the frequency of the electromagnetic radiation
   • Also called Quanta or Packets

6. Annihilation

   • Occurs when a particle and its corresponding antiparticle meet
   • All of the mass and energy is converted into two photons of equal frequency
     • Two photons because momentum is conserved
     • The photons move in opposite directions

7. Pair Production

   • Is the opposite of annihilation
   • The energy of one photon can be used to create a particle and its corresponding antiparticle
     • The photon ceases to exist afterwards

8. Weak Nuclear Force

   • Is responsible for β- decay
   • Called weak because it is only significant in unstable nuclei
     • Stable nuclei are kept from decaying by the strong nuclear force
   • Exchange particles (for β decay) are called W Bosons