Which of the following compounds have a nonzero dipole moment?

Question

a)SiCl4
b)SO3
c)F2
d)BBrF2

Answer 1

The way that I think about questions like these is what would happen if I picked up each of the molecules and threw them up in the air a few time. Something that acts like a baseball or a frisbee would not have a dipole moment because the 'centre of gravity' of the molecule would be the central atom. Using this logic, I can say that option (d) would look lop-sided if I could throw it into the air.