What are the units of a mole?
  1. grams
  2. none (dimensionless)
  3. kilograms
  4. eV
  5. MeV
  6. Joules
  7. Kelvin



Your book gives a value for Boltzman's constant as 8.62 x 10-5 eV/K. Given that value and the average energy in an ideal gas at room temperature (~300 K), estimate the kinetic energy of a helium atom.
  1. 4 GeV
  2. 40 meV
  3. 40 MeV
  4. 4 μeV
  5. 40 eV



What is the approximate mass of a mole of 208Pb atoms?
  1. 208 kg
  2. 208 g
  3. 82 g
  4. 82 kg
  5. none of the above



If I double the pressure of a gas, what will happen to its mean free path?
  1. It will double.
  2. It will be half of what it was before.
  3. It will stay the same.
  4. It will be 1/8 of what it was before.
  5. It will be 8 times what it was before.



In the Rutherford scattering experiment, a more energetic alpha particle would be deflected at a larger angle.
  1. True
  2. False



The model that preceded Rutherfords model of the atom was created by his mentor J.J. Thomson. Thomson postulated that atoms had an extended postively-charged volume in which negatively charged electrons were embedded. The uniformly-distributed postive charge accounted for all of the postive charge and almost all of the mass.

What would Rutherford have seen in his experiment if Thomson was right about the uniform distribution of positive charge, but the mass was concentrated at the center of the atom?
  1. Most of the alpha particles would all have been strong deflected.
  2. The alpha particles would have been weakly deflected, if at all.
  3. The alpha particles would have been absorbed by the atoms.
  4. The alpha particles would have been focussed into a tight beam by the atoms.
  5. Most of the alpha particles would go stright through the foil, but a few would experience large deflections.



What would Rutherford have seen in his experiment if Thomson was right about the uniform distribution of mass, but the positive charge was concentrated at the center of the atom?
  1. Most of the alpha particles would have been strong deflected.
  2. The alpha particles would have been weakly deflected, if at all.
  3. The alpha particles would have been absorbed by the atoms.
  4. The alpha particles would have been focussed into a tight beam by the atoms.
  5. Most of the alpha particles would go straight through the foil, but a few would experience large deflections.