Nuclear Chem Test Review

  1. What is mass defect? Why is the actual mass of an atom lower than the sum?
    The difference between the mass of an atom and the sum of the masses of the e-, p+, and n.

    Because mass --> energy.
  2. What is nuclear binding energy? What can it determine?
    Energy released when a nucleus is formed from nucleons. Also, the amount of energy required to break apart the nucleus. Determines the stability of a nucleus.
  3. The higher the binding energy PER nucleon, the more _____ the nucleus is, and ______ mass defect.
    • stable
    • higher
  4. Large mass loss (converted to energy) means that the nuclide is ______?
  5. Beyond the atomic number __, the element ____, there are no stable nuclides.
    83, bismuth
  6. Above the band of stability means that the nuclide has too many ____ and below it means that the nuclide too little _____.
  7. What is transmutation?
    The change in the identity of a nucleus by changing the number of protons
  8. What is accompanied by radioactive decay?
    particle emissions and/or electromagnetic radiation.
  9. If not much energy is released when a nucleus is formed, then it is _____.
  10. Alpha particles are? What is their charge and symbol? relative mass and penetrating ability?
    2 protons, 2 neutrons. +2 charge. 42He or α. Highest mass, lowest penetrating ability.

  11. Beta particles are? What is their symbol/charge? Relative mass and penetrating ability?
    Like electrons, almost no mass. 0-1β. -1 charge. 2nd lightest and 2nd most penetrating (similar mass and penetrating ability to positrons)
  12. Positrons are? Symbol and charge? Relative mass?
    Like electrons/beta particles but with +1 charge. 0+1β. 2nd heaviest and most penetrating (similar mass/penetrating ability to Beta particles)
  13. Gamma rays are? Symbol are charge? Mass and penetrating ability?
    High energy electromagnetic waves emitted from nucleus as it changes from excited state to ground state. ɣ, 0 charge, 0 mass, highest penetrating ability.
    10N --> 11P + 0-1β
    Beta emission
    11P --> 10N + 0+1β
    Positron emission
    11P + 0-1e --> 10N
  17. In alpha particle emission, the difference between the atomic mass is always multiples of __, and the difference between the atomic number is always multiples of __.
  18. More stable nuclides decay ____, while less stable nuclides decay ____.
    slowly, quickly
  19. What are transuranium elements?
    Any element with more than 92 protons (past Uranium)
  20. In nuclear fission, a heavy nucleus ____ into more ____ nuclei. Releases ____ amounts of energy.
    splits, stable, enormous
  21. In nuclear fusion, low mass nuclei ____ to form a heavier and more ____ nucleus. Releases ______ than fission.
    Combine, stable, even more energy
  22. What is a chain reaction?
    Reaction in which the material that starts the reaction also one of the products and can start another reaction
  23. What is critical mass?
    Minimum amount of nuclide that provides the # of neutrons needed to sustain a chain reaction.
  24. Nuclides with low atomic #s are most stable at what ratio?
    1 N:1 P
  25. Nuclides with high atomic #s are most stable at what ratio?
    1.5 N:1 P
Card Set
Nuclear Chem Test Review