For 6 X
- (with 7e
- each) -->
7e-(6) =
42e- - 6e
- (5 F with three sets of lone pairs each) =
12e- - 2e
-(5 I-F bonds sharing electrons) =
2e- which accounts for lone pair on I
So
7(6) total electrons = 42
42-30 (non-bonding on F) = 12
12-10 (bonding I-F) = 2
2 (lone pair on I)
Now try drawing the Lewis structure if you understand this.Understand that some halogens and other elements can have expanded octets and higher oxidation states.
http://en.wikipedia.org/wiki/Iodine_pentafluoride