Decide if the compound/ion listed can satisfy the octet rule (duet rule for H), if so choose Satisfies Octet Rule from the drop down menu.
If the compound/ion cannot satisfy the octet rule for one of the atoms in the formula, choose one of the following three reasons why;
Too many valence electrons (more than eight), Too few valence electrons (fewer than eight), or Odd # of valence electrons.
SO3
AsF5
PCl5
CO3 2-
NF3
SF3