http://cwx.prenhall.com/bookbind/pubbooks/hillchem3/medialib/media_portfolio/08.html

1. #8 Write the electron configuration for each atom. a. carbon 1s22s22p2 http://cwx.prenhall.com/bookbind/pubbooks/hillchem3/medialib/media_portfolio/08.html

2. #8b. argon argon has 18 electrons 1s22s22p63s23p6 If you add up the superscripts you get the atomic number

3. #8c. nickel nickel has 28 electrons 1s22s22p63s23p64s23d8 or it can be written: 1s22s22p63s23p63d84s2 If you add up the superscripts you get the atomic number

4. #9a. boron boron has 5 electrons 1s22s22p1 One unpaired electron

5. #9b. silicon silicon has 14 electrons 1s22s22p63s23p2 two unpaired electron

6. aufbau principle Pauli exclusion principle Hund’s rule #10

7. Rules for Building of Atoms 1. Electrons fill lowest energy levels first. Aufbau Principle Think: “falling off the bow to the lowest bottom. (of the lake)” Link to Orbital Diagram Practice Page bow of boat More Electron Configuration practice LINK

8. 2. No more than two electrons can be placed in any orbital. Pauli exclusion principle Think: “exclusive dinner for only two”

9. 3. Before a second electron can be placed in any orbital, all the orbitals of that sublevel must contain at least one electron Hund’s Rule Think: “the Huns wanted more space” http://intro.chem.okstate.edu/WorkshopFolder/Electronconfnew.html

10. #11 Explain why the actual electron configurations for some elements differ from those assigned using the aufbau principle. You can see it in this website (click on the pic. when filling the 3d orbitals)

11. #12. Use fig 5.7 to arrange the following sublevels in order of decreasing energy 2p, 4s, 3s, 3d, 3p. 3d 4s 3p 3s 2p Increasing energy

12. #13 Why does one electron in a potassium atom go into the fourth energy level instead of squeezing into the third energy level along with the eight already there? 1s22s22p63s23p64s1 Because the sublevels, 3s and 3p are already filled. The next electron has to find a slightly higher energy level to go to.