Need

1.) put these in order of increasing c−o bond strength, starting with the weakest.

co
co2
co32–

2.) which one of the following pairs of lewis structures represents resonance?

3.)which of the following violates the octet rule?

kcl
icl4−
sif4

4.)read the following statements. which ones are correct? be sure to explain how you know.

bf3 and pf5 are examples of violations of the octet rule.
bf4− and bf3-nh3 are examples of violations of the octet rule.
expanded valence shells occur most often when the central atom is bonded to a small, electronegative element.
the central atoms most capable of having expanded valence shells come from rows 3, 4, and 5 of the periodic table.

if you can can you provide explanation as well you