Edexcel P2 Unit 5.txt

  1. What is the name of the process whereby a nucleus is split into smaller parts
    Nuclear fission
  2. Which particle must be absorbed by uranium-235 or plutonium-239 for fission to occur?
    A neutron
  3. What is produced when an unstable nucleus splits into two smaller nuclei?
    Energy, and 2 or 3 neutrons
  4. What is nuclear fusion?
    The joining of two atomic nuclei to form a larger one

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  5. What is the name of the process by which energy is released in stars?
    Nuclear fusion
  6. What is the role of the moderator in a fission reactor?
    It slows down the neutrons so that they are slow enough to be absorbed by nuclei (and so continue the chain reaction)
  7. How is a nuclear fission reactor controlled?
    • By control rods which can be lowered into the reactor to absorb neutrons and so slow down the chain reaction
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  8. What does the atomic number of an atom represent?
    The number of protons in the atom
  9. Which radioactive particle is made of two neutrons and two protons (a helium nucleus)?
    • Alpha particle
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  10. Which radioactive particle is an electron?
    • Beta particle
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  11. Why is nuclear fusion hard to achieve?
    The positively charged nuclei will repel each each other and overcoming this requires a large amount of energy.
  12. Which type of radiation is not a particle?
    • Gamma ray 
    • (it is electromagnetic radiation)
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  13. Order the 3 types of radiation by decreasing ionising power
    • 1) Alpha (most ionising), 
    • 2) beta, 
    • 3) gamma (least ionising)
  14. Which type of radiation has a range of 2-3 cm in air?
    Alpha particles
  15. Which type of radiation is stopped by thin aluminium?
    • Beta particles
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  16. What does the atomic number of an atom tell us?
    How many protons it contains
  17. What does the mass number of an element tell us?
    The number of protons and neutrons in an element added together.
  18. What is an ion?
    An atom that has lost or gained electrons
  19. In nuclear fission what is a chain reaction?
    When the neutrons released from the splitting of one nucleus hit other nuclei and make them split and release more neutrons. (It goes on and on and on and on - just like the links in a chain)
  20. In nuclear fission, what are daughter nuclei?
    The smaller nuclei produced from the splitting of a larger nucleus
  21. These are the steps in making electricity from a nuclear reactor. Put them into the right order:
    a) The turbine turns the generator
    b) Water is heated up
    c) Nuclear reactor produces heat
    d) Water turns to steam
    e) The generator makes electricity
    f) Steam turns the turbine
    • Nuclear reactor produces heat
    • Water is heated up
    • Water turns to steam
    • Steam turns the turbine
    • The turbine turns the generator
    • The generator makes electricity
  22. What process in science do new ideas have to go through before they are accepted?
    • Evidence has to be produced
    • Experiments must be repeated
    • Evidence is peer reviewed (checked by other scientists)
Card Set
Edexcel P2 Unit 5.txt
Edexcel P2 Unit 5