Solutions to Electron Configurations Homework Set

  1. Write the electron configuration (ie: 1s2, 2s1), orbital energy diagram, and orbital box diagram for,
    1. H, Li, Na, and K
      Element Configuration Short
      H 1s1 1s1
      Li 1s2, 2s1 [He] 2s1
      Na 1s2, 2s2, 2p6, 3s1 [Ne] 3s1
      K 1s2, 2s2, 2p6, 3s2, 3p6, 4s1 [Ar] 4s1

      I am unable to create box diagrams or energy level diagrams (without great effort) on the computer so you will have to look in your textbook for examples of thes. See page 373 in Kotz & Treichel for an example of the box diagram, and page 365 in Kotz & Treichel for an example of the energy level diagram (Fill this in with the arrows for the electrons).

    2. Be, Mg and Ca
      Element Configuration Short
      Be 1s2, 2s2 [He] 2s2
      Mg 1s2, 2s2, 2p6, 3s2 [Ne] 3s2
      Ca 1s2, 2s2, 2p6, 3s2, 3p6, 4s2 [Ar] 4s2
    3. C, Si and Ge
      Element Configuration Short
      C 1s2, 2s2, 2p2 [He] 2s2, 2p2
      Si 1s2, 2s2, 2p6, 3s2, 3p2 [Ne] 3s2, 3p2
      Ge 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p2 [Ar] 4s2, 3d10, 4p2
    4. F, Cl and Br
      Element Configuration Short
      F 1s2, 2s2, 2p5 [He] 2s2, 2p5
      Cl 1s2, 2s2, 2p6, 3s2, 3p5 [Ne] 3s2, 3p5
      Br 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p5 [Ar] 4s2, 3d10, 4p5
    5. Fe, Ni and Zn
      Element Configuration Short
      Fe 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d6 [Ar] 4s2, 3d6
      Ni 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d8 [Ar] 4s2, 3d8
      Zn 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10 [Ar] 4s2, 3d10
    6. Cl1- and K1+
      Element Configuration Short
      Cl1- 1s2, 2s2, 2p6, 3s2, 3p6 [Ne] 3s2, 3p6 [Ar]
      K1+ 1s2, 2s2, 2p6, 3s2, 3p6 [Ne] 3s2, 3p6 [Ar]
    7. Mg2+ and F1-
      Element Configuration Short
      Mg2+ 1s2, 2s2, 2p6 [He] 2s2, 2p6 [Ne]
      F1- 1s2, 2s2, 2p6 [He] 2s2, 2p6 [Ne]
  2. Use a blank periodic table and write in the periodic trends for,
    1. atomic size.
      • Larger as you go down and to the left. Cs is very large.
      • Smaller as you go up and right. He is very small.
    2. ionization energy
      • Increases as you go up and to the right. It is VERY difficult to take an electron from He.
      • Decreases as you go down and left. It is VERY easy to take ana electron from Cs.
    3. electron affinity
      • Increases as you go up and to the right. It is VERY easy to add an electron to F. (NOTE: Nobel gases are very difficult to add an electron to).
      • Decreases as you go down and left. It is VERY difficult to add an electron to Cs.
    4. ion size Here it is important to distinguish between posative ions and negative ions. Generally negative ions are larger than posative ions. For each type of ion:
      • Larger as you go down and to the left. Cs1+ is a very large posative ion and Te2- is a very large negative ion.
      • Smaller as you go up and right. Al3+ is a very small posative ion and F1- is a small negative ion.
  3. Element 112 was first produced "February 9th, 1996 at 22:37 at the Gesellschaft für Schwerionenforschung in Darmstadt, Germany". Write the electron configuration for this element, write a set of quantum numbers for the valence electrons, and add the element to the periodic table in the front of your textbook.
    1. Electron Configuration: 1s2, 2s2, 2p6, 3s2, 3p6, 4s2, 3d10, 4p6, 5s2, 4d10, 5p6, 6s2, 4f14, 5d10, 6p6, 7s2, 5f14, 6d10
    2. write a set of quantum numbers for the valence electrons
      n l ml ms   n l ml ms
      8 0 0 +1/2   8 0 0 -1/2
      6 3 -3 +1/2   6 3 -3 -1/2
      6 3 -2 +1/2   6 3 -2 -1/2
      6 3 -1 +1/2   6 3 -1 -1/2
      6 3 0 +1/2   6 3 0 -1/2
      6 3 1 +1/2   6 3 1 -1/2
      6 3 2 +1/2   6 3 2 -1/2
      6 3 3 +1/2   6 3 3 -1/2
      7 2 -2 +1/2   7 2 -2 -1/2
      7 2 -1 +1/2   7 2 -1 -1/2
      7 2 0 +1/2   7 2 0 -1/2
      7 2 1 +1/2   7 2 1 -1/2
      7 2 2 +1/2   7 2 2 -1/2
    3. Add the element to the periodic table in the front of your textbook.
      The atomic number is 112 and the atomic weight is (277). The atomic weight should be in parenthesis since it is the mass of the most common (and so far the only) isotope and this isotope is not stable.
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