Indicate the direction of the important bond moments in each of the following compounds (neglect C-H bonds). You should also give the direction of the net dipole moment for the molecule. If there is no net dipole moment, state that μ = 0 D.
(a) cis-CHF==CHF
(b) trans-CHF==CHF
(c) CH2==CF2
(d) CF2==CF2