Nuclear physics

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    Created by
    molly

    Cards (27)

    • what is the structure and size of an atom
      positively charged nucleus 1x10^-14m
      with shells of negative electrons orbiting it
      atom = 1x10^-10m
    • what affects the electron arrangement in an atom?
      Electrons are in shells at different energy level
      when they absorb EM radiation they go up shells
      when they emit EM radiation they do down shells
    • what is mass number
      Protons + neutrons
    • What is atomic number
      proton number
    • what is an isotope
      An Atom with the same number of protons but a different number of neutrons
    • why is a scientific model or theory changed
      there is new evidence that doesn’t fit the current model
    • what was the plum pudding model
      the atom Is a ball of positive charge with negative electrons embedded in it
    • what were the discoveries of the alpha scattering experiment
      fired alpha particles at thin gold foil
      most went straight through the atom is mostly empty space
      some deflected showing the atom has a positive nucleus where mass is concentrated
    • what did Bohr discover
      Electrons orbit the nucleus in shells at specific distances from the nucleus
    • What was discovered after Bohrs discovery
      The proton
    • what did Chadwick discover
      The neutron which lead to understanding of isotopes
    • what is activity and how is it measure
      activity is the decay of an unstable nucleus measure in bequerels (Bq)
    • What is count rate how is it measured
      the number of decays per second
      measured using a Geiger muller tube
    • what are the types of nuclear radiation
      Alpha(α)- most ionising, least penetrating (only stopped by paper, can only move a few cm in air)
      Beta(β)- middle ionising, middle penetrating (stoped by 3mm aluminium, moves 1m in air)
      Gamma(γ)-low ionising, highest penetrating(stopped by thick lead and concrete, can move kilometres in air)
    • what is a half life (the equation)
      The time taken for the count rate of a radioactive material to half
      number of decayed = initial number x 0.5^half lives
    • why do we use half lives
      radioactive decay is random and spontaneous so a half life is like an average
    • what is contamination
      why is it a hazard
      what are the uses
      when an object has radioactive material on it
      hazard- ionising cells
      used for medical tracers and to check for leaks in pipes
    • What is irradiation
      what are the hazards
      what are the uses
      when an object is exposed to radiation
      hazard- ionising cells
      used to kill cancer
    • what are the sources of background radiation
      Radon gas
      medicine
      nuclear weapons test
      nuclear power plants
      cosmic rays
    • Describe the nature of radioactive decay
      Random and spontaneous
    • what are the uses of radiation
      alpha - smoke detectors
      beta - medicine
      gamma - medical tracers, gamma knife, sterilisation
    • how to reduce the hazard of radiation
      Distance
      shielding (lead apron, ppe)
      Limit time
    • what is the importance of pear review
      check for bias and inaccuracy
      other scientist can learn from findings and improve it
    • How is radiation dose measured
      Sieverts
    • What is the process of nuclear fission in A nuclear reactor
      nuclear fuel is held in rods
      when triggered a neutron is fired at the fuel
      the neutron is absorbes causing the nucleus to split into 2
      2 or 3 neutron and gamma rays are released
      the neutrons are absorbed by other nuclei forming a chain reaction
    • how is fission in a reactor different to in a nuclear bomb
      fission in a reactor is controlled by control rods which absorb neutrons to slow down the chain reactions
    • what is nuclear fusion
      when 2 small nuclei collide to form 1 larger nucleus
      some mass is converted to energy
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