Question

how to determine the elements that are expanded octet and incomplete octet?

Answer 1

do you mean in general or from a lewis diagram or...

Answer 2

for the lewis diagam

Answer 3

ok, well first you know what the octet rule is right?

Answer 4

yea..I understand that one

Answer 5

elements of period 3 and above can expand their valence shells to include extra lone pairs or bonded pairs

Answer 6

but incomplete octet - in your course or book, do they mean the other exceptions to the octet rule (there aren't enough valence elctrons or there are odd numbers)?

Answer 7

in any case, you can always count the number of valence electrons and bond pairs and see if anything is different than it should be

Answer 8

too little = incomplete (many things with Al, Be, B) and "free radicals"
to many = expanded (ICl4, phosphorus (PCl5)

Answer 9

i have to go, maybe this would help http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Exceptions-to-the-Octet-Rule-573.html good luck

Answer 10

oh...thank you!