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(Radioactivity, Energy, Waves) - Coggle Diagram

- - - - Alpha decay.
        
        In alpha radiation , 2 neutrons and 2 protons are emitted. As a result , the mass number decreases by 4 whilst the atomic number decreases by 2.
        
        A new element is always created.
      - Beta decay
        
        A neutron has turned into a proton and is not emitted outwards.
        
        An electron is emitted.
        
        The mass number is unchanged whilst the atomic number increases by 1 due to the extra proton.
        
        A new element is formed.
      - Gamma radiation.
        
        Gamma is an EM wave/
        
        There is no change in mass.
      - Positron decay.
        
        A positron is a high speed particle with the same mass as an electron but a charge of +1/
        
        During positron decay , a proton becomes a neutron and a new positron forms.
        
        The atomic number decreases by 1 nut the mass stays the same.
    - - Alpha particles have a higher mass compared to batá particles. This means that they are more ionizing. Energy lost from ionization means that the particles can not pernitrate as far and so they are more likely collide with atoms due to their size,
  - - - The sources can often come from cosmic rays , food , x rays and rocks.
      - Radiation is always measured with a G-M counter in Bq.
    - - There is a known proportion of activity when rocks are formed. This can be used to measured the proportion of uranium now. Compare the original amount of uranium with the activity of uranium now. This will help determine the number of half lives that have elapsed. thus , you can determine the age,
  - - - Alpha is the most ionizing.
      - Beta is moderately ionizing.
      - Gamma is least ionizing.
    - - Gamma is stopped by several Cm of lead and concrete.
        
        Indefinate range.
      - Beta is stopped by aluminum foil.
        
        Few metres in range.
      - Alpha is stopped by paper and air.
        
        Range of 5-10 cm.
- - - - All metals are good conductors as they have delocalized electrons.
        
        A metal is made up of cations sounded by a sea of electrons.
        
        When head is applied , the positive metal atoms begin to vibrate and gain kinetic energy and begin to vibrate. Kinetic energy is transferred through the metal through the delocalized electrons.
        
        A duvet traps in air because there is not a lot of air space to let the transfer of energy through meaning that there is less heat transfer will take place.
        
        Havin a cavity wall can make a major difference.
        
        Having double glazed windows will prevent convection and conduction.
        
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      - Insulators are materials that do not allow for the transferee of energy,
        
        Wood and plastics are poor conductors.
        
        They have no delocalized electrons.
        
        Polyisoprene is a poor conductor because it contains a lot of air space and does not have any delocalized electrons as the air space is very far apart.
    - - A radiator is a good example. At the bottom , the liquid / gas is heated. As a result , the partials contain kinetic energy and the liquids / gases is spun and occupies more space. Because they occupy more space , they become more dense and rise and then they fall again.
        
        A lid or a layer of air over the polystyrene cup will stop the convection.
        
        Convection only occurs in liquids and gasses.
    - - Radiation is caused by electro magnetic waves.
        
        It can travel through solids , liquids and gasses.
        
        In a thermos flask , there is a vacuum which has no particles. This stops convection and conduction.
        
        The silver surface reflects IR waves.
- - - - Longitudinal waves have periods of compression and refraction.
    - - Water waves , light waves are any waves on the EM
  - - - wave speed = m/s
      - Frequency = Hz
        
        Frequency is the number of waves per second.
      - Wavelength = m
    - - The time needed to produce 1 wave.
      - Time period is feq =1/time period