SCI 270: On Nuclear Technology Practice Problems  
Please study and then test your understanding using these problems. Please do not hand in any answers for marking.

2. Natural Units: electrons, atoms, molecules, and natural constants

  1. Express the rest mass of an electron in the following units. Please use 1e-6 to mean 10-6 in your expressions.

    ___________ J

    ___________ MeV

    ___________ g

    ___________ kg

    ___________ amu

  2. Complete this table for the properties of an electron.

    Charge in C Charge in esu Spin Magnetic moment





  3. Give these fundamental constants so that you are familar with the physical quantities.

    Charge for one mole of electron F = _____________ C
    Avogadro's number NA = _____________ particle mol-1
    Estimate the charge of an electron
    from the two quantities given above

    The Planck constant h = _____________ J s-1

  4. An electron has a kinetic energy of 1 eV. Give the following:

    Kinetic energy = __________________ J Velocity of the electron __________________ m/s

    Force = _____________ N

  5. Estimate the Coulomb force of attraction when the electron is 53 pm (1 pm = 1e-12 m) from a proton. This is the Bohr model for the H atom.

  6. To decompose 36 g of water, 4 F charges must pass through the electrodes. If the voltage applied is 1.23 V, calculate the energy required for this decomposition.

    36 g water = _____________ mol
    Number of molecules in 36 g water = _____________ molecules
    Number of atoms in 36 g water = _____________ atoms
    Energy = _____________ keV
    Energy required to decompose
    a water molecule =
    _____________ keV
    Answers to Practice Problems 2 are available, but do your part first. Your skills are tested, not the answers.