I'm taking this lesson now, so imma help u ( if u need anything else ask me)
so given Molar mass= 32 g/mol
molar mass= (empirical formula) n
32 = (14x1 + 2x1) n
32 = 16 n , so n= 2
so, molecular formula= N2H4
Vanadium
V 1s²2s²2p⁶3s²3p⁶4s²3d³
I believe the answer is A. :)<span />