Textbook 2E13C

[Connie Liang 3L]

How come in the Lewis Structure for IO3- all the oxygens are single bond instead of double bonded? With double bonds, the Lewis Structure would still have a charge of -1 and have the same molecular shape.

[Gwendolyn Hill 2F]

Pretty sure that since I is a larger molecule, the single bond representation is more accurate. I'm sure that having resonance structures combining would give us a bond length somewhere in between, but it might be because single bonds are longer and I is a larger molecule, and double bonds are shorter. That might not be correct, but that's how I might think about it.

[Sean Phen]

I am not exactly sure about this problem because I did not do it yet. But, there are sometimes more than one way that you can make the Lewis structure.

[Connie Liang 3L]

Pretty sure that since I is a larger molecule, the single bond representation is more accurate. I'm sure that having resonance structures combining would give us a bond length somewhere in between, but it might be because single bonds are longer and I is a larger molecule, and double bonds are shorter. That might not be correct, but that's how I might think about it.

Thanks Gwendolyn! I just read in the textbook that it's difficult for atoms beyond Period 2 to form double bonds because the atoms are so large that their orbital overlaps are pretty weak. Thanks for your clarification :)