Which one of the following compounds does not follow the octet rule?

Question

a) NF3
b) CF4
c) SF4
d) PH3
e) HCl

I know I can eliminate A and B because nitrogen and carbon follow the octet rule. I know I can eliminate E because the total amount of valence electrons in HCl is 8. I am not sure about C and D.

Answer 1

We can't draw structures on this forum but these two links should help you decide.
https://terpconnect.umd.edu/~wbreslyn/chemistry/Lewis-Structures/lewis-structure-for-PH3.html

https://terpconnect.umd.edu/~wbreslyn/chemistry/Lewis-Structures/lewis-structure-for-SF4.html

Answer 2

So it looks like SF4 does not follow the octet rule?

Answer 3

That's right.