Chem 1020 Summer 2007 Name: ___Answer key_______________________
Quiz 2 Form A
1. Write the abbreviated electron configuration for Pb.
[Xe] 6s2 4f14 5d10 6p2
2. Write the full electron configuration for the Ca+ ion.
1s2 2s2 2p6 3s2 3p6 4s1 (Many of you just wrote neutral calcium’s configuration. The
Ca+ ion has one fewer electron.)
Is this a stable ion? Why or why not?
NO! Stable ions have a noble gas electron configuration. We would never see a Ca+
ion in a compound.
3. Draw the Lewis electron-dot structure for NOF. (Remember which one is the
central atom! Make sure the correct total number of valence electrons is shown.)
Total # ve = 5 + 6 + 7 = 18 ve (all of which must be accounted for in the structure!)
Even with the hint in the question, many of you put oxygen as the central atom.
Remember, the central atom is the first element in the formula (but not hydrogen).
This is a neutral molecule, so all atoms will make their normal number of bonds.
The central N has 3 bonds, O has two and F has one. So, if we put it together and
complete the octets, this is the structure:
O N
F
