P4 - Atomic Structure

P4 - Atomic Structure

1. Nucleus

   • Proton
     • Mass = 1
     • Charge = +1
   • Neutron
     • Mass = 1
     • Charge = 0
   • Electron
     • Mass close to 0
     • Charge = -1

2. Radioactivity

   • 3 types
     • Gamma
       • Mass : 0
       • Charge : 0
       • Weak ionisation
       • Penetration : few m of concrete / lead
     • Beta
       • Mass : tiny
       • Charge : 1-
       • Fairly strong ionisation
       • Penetration : few m in air
     • Alpha
       • Mass : 4
       • Charge : 2+
       • Strong ionisation
       • Penetration : few cm in air
   • Tracers
   • Measuring
     • Geiger-Muller tube
   • Background
   • Isotopes
     • An atom with a different number of neutrons but the same number of protons.
   • Half Life

3. Properties of Radiation

   • Alpha is the least penetrating
     • Beta is quite penetrating
       • Gamma is the most penetrating
   • Alpha is the most ionising
     • Beta is quite ionising
       • Gamma is the least ionising

4. Irradiation and Contamination

   • Irradiation is when something is exposed to radiation.
   • Contamination is when particles from the radiation attach themselves to something

5. Fission and Fusion

   • Nuclear fission is when there is a spilt between a large nucleus and it forms two smaller nuclei.
   • Nuclear fusion is when two small; nuclei join together to form one large nucleus.