Pick three examples from each of the following sets (that makes 18 examples, total):

1. linear (AX2)
2. bent (AX2E)
3. bent (AX2E2)
4. trigonal planar (AX3)
5. tetrahedral (AX4)
6. trigonal pyramidal (AX3E)

and, for each set:

1. Determine the overall number of valence electrons for each of the three examples.
2. Draw a proper "sigma" structure (no double bonds) for each example.
3. Discuss the similarity or differences in central atom bonding (number of sigma bonds, number of lone pairs) among the three examples.