Matter and Radiation

Matter and Radiation

1. Inside the Atom

   • Protons and neutrons
     • mass number= Nucleon number
     • Atomic number= Proton Number
   • Isotopes
   • Specific charge of a particle is it's CHARGE DIVIDED BY ITS MASS
     • measured in coulombs per kilogram always state that you are excluding the mass of electrons because it is negligible and state the mass of an electron

2. Stable and Unstable Nuclei

   • Strong Nuclear Force
     • overcomes force of electrostatic repulsion between the protons in the nucleus- keeps the nucleus together
     • Range of 3-4 Femtometres but the range of electrostatic repulsion between two charged particles is infinite
     • attractive force from 3/4 fm to 0.5fm. distance smaller than this it becomes a repulsive force to stop protons and neutrons being pushed togehter
     • has the same effect on two protons as it does two neutrons / a proton and a neutron
   • Radioactive Decay
     • Beta minus Decay
     • alpha decay
     • gamma decay
       • emitted by a nucleus with too much energy
       • following apha or beta emission

3. Photons

   • wavelength = c over F
   • plank's constant is given
   • annihilation
     • particle and antiparticle collide and vanish leaving two photons
     • minimum energy of photons produced =2hf=2E(e is the rest energy)
   • Pair Production
     • One photon splits into a particle and an antiparticle
     • hfmin= 2E where E is the rest mass of the particle/antiparticle
   • e photon =hf

4. Particles and Antiparticles

   • For each particle there is an antiparticle
   • equal in mass opposite in charge
   • When they collide they annhialate on another

5. How particles Interact

   • exchange particles explain forces between elementary particles
   • exchange particles cause the transfer of momentum, energy or charge
   • Strong Force
     • experienced by all hadrons
     • when particles decay via the strong force quarks can be created or destroyed but not change from one to another
     • Strangeness is conserved
   • Weak Force
     • experienced by all particles
     • responsible for changing one fundamental particle into another
   • Electron capture
     • A proton in a"proton rich" nucleus interacts with an inner electron via the weak interaction, this turns the proton into a neutron and the electron into a neutrino 
   • Classification of Particles
     • Classification of Particles

6. Classification of particles

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