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Physics - Coggle Diagram

- - - - Negatively charged particles with a relative mass of 1/2000
        
        Electrons orbit the nucleus in energy levels
        
        The first energy level can only hold 2 electrons
        
        The second and third energy level can only hold 8 electrons
        
        The higher the energy level, the further away from the nucleus it is
        
        Increasing energy due to greater distance from the nucleus
    - - Neutral particles that have a relative mass of 1
    - - Positively charged particles with a relative mass of 1
    - - The number of protons
    - - Isotope
        
        Atoms of the same element that have a different number of neutrons
      - The number of protons and neutrons, particles in the nucleus
  - - - Plum Pudding Model
        
        Discovery of electrons
        
        A sphere of positive charge with negatively charged electrons dotted around inside it, "Plum Pudding"
    - - Small indivisible spheres
        
        All matter is made up of atoms
        
        Atoms cannot be broken down into anything simpler
        
        Atoms of a specific element are identical to each other
        
        Symbols for elements
        
        Determined atomic weight
    - - Matter was made up of indivisible particles
    - - Nuclear Model
        
        Alpha scattering experiment
        
        Most alpha particles went through it
        
        Atoms are mostly empty space
        
        Some alpha particles were deflected backwards
        
        The atom contains a small heavy centre
        
        Nucleus
        
        Some alpha particles were deflected of their path
        
        The nucleus has a strong positive charge
    - - Electrons orbit in shells
        
        Planetary model
        
        Could explain findings better than the nuclear model
    - - Discovered the neutron
  - - - Irradiation
        
        The process of exposing a material to alpha, beta or gamma radiation
        
        Used in sterilisation
        
        Food
        
        To kill any microorganisms within it
        
        Prevents the food from going mouldy for longer
        
        2 more items...
        
        Surgical Equipment
        
        To kill any microorganisms
      - Contamination
        
        The unwanted presence of materials containing radioactive atoms on other materials
        
        Airtight safety clothing and safe handling of sources
    - - Half life
        
        Time it takes for the activity to fall to half of its original value
        
        The time it takes for the number of nuclei of a sample of radioactive isotopes to decrease by half
      - Each nuclei has an equal chance of decaying
        
        It cannot be known which particular nucleus will decay
        
        It cannot be known what time a particular nucleus will decay
    - - Neutron
        
        Neutron
        
        n
        
        Found in the nucleus
        
        No charge
      - Gamma
        
        Gamma Waves
        
        γ
        
        Electromagnetic waves
        
        Shortest wavelength
        
        Highest energy of all electromagnetic Waves
        
        No charge
        
        2 more items...
      - Beta
        
        Beta Particle
        
        β
        
        Fast moving electrons
        
        A neutron from the nuclei changes into a proton and an electron
        
        Charge of -1
        
        2 more items...
      - Alpha
        
        Alpha Particles
        
        α
        
        Same as a helium nucleus
        
        Two protons and two neutrons
        
        Charge of + 2
        
        1 more item...
    - - Activity
        
        Detection
        
        Geiger-Muller Tube
        
        Connected to a Geiger counter
        
        The Geiger Counter counts how many ions are created
        
        Ions are created as the radiation passes in the tube
        
        The rate at which the unstable nuclei from a source of radiation decays
        
        Measured in Becquerels
        
        1 Becquerel = 1 nucleus decaying in 1 second
        
        Bq
      - Emit radiation
    - - Too much or too few neutrons
      - Too large
        
        Radiation is emitted to make the nucleus stable
        
        Radiation is:
        
        Random
        
        We cannot know which particular nucleus will decay
        
        As it reduces the overall amount of energy
    - - All work should be peer reviewed
        
        Other scientist can learn from the findings
        
        Marie curies findings were looked at by lots of other scientists
        
        Their work can be checked for accuracy
        
        Work with radiation must be peer reviewed, as it is important for human health
        
        It makes the findings more common knowledge
  - - - Two sources
        
        Natural
        
        Rocks
        
        Cosmic Rays
        
        Foods
        
        Man-made
        
        Exposure from medical testing
        
        Nuclear Fallout
      - The radiation that is present all around in the environment
        
        Radiation dosage is measured in Sieverts
        
        1 Sievert is a lot of radiation
        
        Could cause acute radiation sickness
        
        Levels of background radiation are affected by
        
        Occupation
        
        Location
    - - Different isotopes have very different half lifes
        
        Very short half lives
        
        Will decay quickly
        
        Short half life can be advantageous
        
        But large amounts can be dangerous as lots of radiation is released in a short amount of time
        
        Long half lives
        
        Will decay slowly
        
        Will not emit a lot of radiation quickly
        
        But will remain radioactive for a long period of time
        
        Risk of contamination for a much longer period of time
        
        Buried underground to prevent it being released into the environment
    - - Medical tracers
        
        The amount of the isotope is also minimised
        
        Isotopes used have short half lives
        
        Around a few hours
        
        Long enough to carry out the procedure
        
        Short enough to minimise the damage
        
        Patient harm is minimised as they are the least ionising
        
        Gamma emitters are used as they are highly penetrating
        
        A radioactive isotope that can be used to track the movement of substances
      - Radiotherapy
        
        Treatment of cancer using radiation
        
        It can cause it, but it is also highly effective at treating it
        
        External
        
        Beams of gamma radiation are targeted at the tumour
        
        Healthy tissue is normally shielded to avoid unnecessary damage
        
        Internal
        
        Small pellets of radioactive material can be inserted directly into the tumour
      - Sterilising medical equipment
        
        Gamma radiation is used
        
        Most penetrating
        
        Can be used to sterilise all sides
        
        Does not have to be taken out of its package
      - Risks
        
        Radiation can
        
        Kill or damage living cells
        
        Benefits of using radiation outweigh the risks
        
        Use of it is kept to a minimum
        
        Cause cancer
        
        Cause mutations in the DNA