AQA Physics P2.5

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AQA Physics P2.5
2015-03-13 14:07:22
AQA Physics P2

AQA Physics P2.5
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  1. Which particles are inside an atomic nucleus?
    • Protons
    • Neutrons
  2. Which particles orbit the atomic nucleus?
  3. What are the relative masses of
    a) protons,
    b) neutrons
    c) electrons
    • Relative masses
    • protons=1
    • neutrons=1,
    • electrons= 1/1800
  4. What are the relative electric charges of
    a) protons,
    b) neutrons
    c) electrons
    • Charges
    • Protons = +1
    • neutrons = 0,
    • electrons = -1
  5. If an atom has 10 protons, how many electrons will it have?
    10  (in an atom, the number of protons and electrons are equal)
  6. What name is given to an atom which has gained or lost electrons?
  7. What does the atomic number of an atom represent?
    The number of protons in the atom
  8. What does the mass number of an atom represent?
    The total number of protons and neutrons in the atom
  9. Name two natural sources of background radiation
    • rocks
    • cosmic rays from space
  10. Name two man-made sources of background radiation
    • nuclear accidents
    • nuclear weapons tests
  11. Which radioactive particle is made of two neutrons and two protons (a helium nucleus)?
    Alpha particle

  12. Which radioactive particle is an electron?
    Beta particle
  13. Which type of radiation is not a particle?
    • Gamma ray
    • (it is electromagnetic radiation)
  14. Order the 3 types of radiation by decreasing ionising power
    • 1) Alpha (most ionising),
    • 2) beta,
    • 3) gamma (least ionising)
  15. Which type of radiation has a range of 2-3 cm in air?
    Alpha particles
  16. Which type of radiation is stopped by thin aluminium?
    • Beta particles
  17. Which type of radiation has a negative charge?
    Beta particles
  18. Which type of radiation is not deflected by electric and magnetic fields
    • Gamma rays
  19. Which type of radiation is deflected the most by electric and magnetic fields?
    • Beta particles
  20. Why are alpha particles deflected less by magnetic and electric fields than beta particles?
    Alpha particles have twice the charge (so should be deflected more) but have 7000 times more mass so are actually harder to deflect.
  21. Which type of radiation is used in smoke detectors?

    Alpha particles 
  22. What was the name of the model of the atom that considered the negative charges spread evenly throughout the atom?
    • The plum pudding model
  23. What did Rutherford do that provided evidence against the plum pudding model of the atom?
    • He fired alpha particles at gold foil.
    • He expected that they would be deflected a small amount but found that most went straight through, a few were deflected, and some bounced back.
  24. Which sort of radiation is used to measure paper thickness?
    Beta particles
  25. Which sort of radiation is used as a tracer in medical applications?
    Gamma rays
  26. Which sort of radiation is used to detect cracks in pipes and other metal structures?
    Gamma rays
  27. What is the half-life of a radioactive isotope?
    • The time taken for the number of radioactive nuclei in a sample to halve, or, the time taken for the decay count rate to halve. (These give the same number)
  28. What are isotopes?
    • Versions of an element that have different numbers of neutrons
  29. Which radioactive isotope is used to determine the approximate age of very old things that were once living?
  30. Name 3 ways in which radioactive waste could be disposed of.
    • Any 3 of:
    •   inside bore-holes in solid rock,
    •   at sea in special containers,
    •   bury under the seabed,
    •   launch it into space,
    •   at the edge of tectonic plates so that it is dragged into the Earth's mantle
  31. Name 3 ways that workers using radiation protect themselves against exposure
    • Take care to keep exposure to a minimum
    • Use lead screens where possible (eg taking x-rays)
    • Wear radiation badges (to monitor the radiation)
  32. What is the main health problem that exposure to radiation to cause?