Textbook 2C7 Iodine

[ALee_1J]

Determine the number of electron pairs (both bonding and lone pair) on the iodine atom in: ICl₂⁺, ICl₄^-, ICl₃, and ICl₅

How do you figure out how many electron pairs iodine has?
I noticed that sometimes iodine has more than four bonds but also has lone pairs and other times it has only two bonds and two lone pairs.

[Marisa Gaitan 2D]

Draw the lewis structures by adding up all the electrons in the ion/molecule. Then divide by 2 to get the number of electron pairs. This will help you see how many pairs are needed to be drawn. Make sure to take formal charge into consideration, "balancing" the molecule so each is closest to zero and adds up to the final charge of the molecule. For ICl²⁺ it has 20 electrons total, so 10 pairs. Formal charge tells you that I has two single bonds and two lone pairs.

[ColmConnolly3D]

I just want to add that for most molecules it would be good to make use of the octet rule first, iodine is kind of an exception to the standard operating procedure