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Revision on pages 92-96, Questions - Coggle Diagram

- - - - stopped by paper
      - made up of positively charged particles
        
        these could be used to probe the atom
      - His students - including Hans Geiger, inventor of Geiger counter - carried out further investigations
        
        They put a narrow beam of alpha particles was directed at a thin metal foil, and were surprised to find that some of the particles rebounded from the foil.
        
        proved that this happens as every atom has a positively charged nucleus - contains most of the mass of the atom.
        
        nucleus contains two types of particles - protons and neutrons
    - - went through the paper
  - - - More penetrating than beta radiation
- - - - The apparatus was in a vacuum chamber to prevent air molecules absorbing the alpha particles. The
- - - - made up on 2 protons and 2 neutrons
      - relative mass is 4
      - relative charge is +2
    - - atomic number goes down by 2
      - mass number goes down by 4
      - mass and charge of nucleus are both decreased
    - - An electron created and emitted by a nucleus that has too many neutrons compared with its protons
      - a nuetron in the nucleus changes to a proton and a b particle - like an electron - and is emitted.
      - relative mass of a b particle is zero
      - relative charge is - 1
- - - - Write 2 differences between the radiation from uranium and the radiation from a lamp
        
        radiation from uranium comes in particles and radiation from a lamp comes in waves
        
        a lamp will emit light whereas uranium will not
    - - Write 2 differences between radioactive atoms compared with the atoms compared with the atoms in a lamp filament
        
        decay of radioactive atoms cannot be prevented, whereas in a lamp filament the atoms stop emitting radiation when the lamp is turned off
        
        radioactive atoms have an unstable nuclei where as those in a lamp filament have stable nuclei
  - - - i
        
        The radiation from a radioactive source is stopped by paper. Name that type of radiation the source emits.
        
        alpha
      - ii
        
        The radiation from a different source goes through the paper. Name the type of radiation this source emits.
        
        beta
    - - Name the type of radiation from radioactive sources that is the most penetrating
        
        gamma
  - - - Because some types of radiation - like alpha - is made up of positively charged particles. This meant they could be used to probe the atom
  - - - a
        
        Describe the substance that made the Geiger counter click
        
        a radioactive substance
      - b
        
        When the Geiger tube was near the substance, the counter clicked much less when a sheet of paper was placed between the substance and the tube. Explain why the counter clicked much less.
        
        Because alpha radiation is stopped by paper.