posted by Confused .
For each of the bonds listed below use hybridized orbitals to classify the type of sigma bond that is formed between the two atoms.
a) The sigma bond between boron and hydrogen in BH3
answer: sp^2 - p
b) the sigma bond between S and fluoride in SF4.
answer: sp^3d - p
I understand how to obtain the first part of the answer, but not the second.
You're forgetting that unshared pair of electrons on the S atom. Here is the Lewis dot structure.
That AB4U makes it trigonal bi-pyramid and that accounts for the dsp3 for SF4