How many valence electrons are in the acetate ion c2h3o2-
?

Yes she is correct. the answer is completely correct

There is one s orbital, and there are three p orbitals, five d orbitals, and seven f orbitals. thus, the answer is b. do not confuse the number of orbitals in a subshell with the number of electrons the subshell can hold. each orbital can hold two electrons, so the capacity of an nf subshell is 14 electrons.

The answer is true for your question.