Question

Which of the following would have a permanent dipole moment ?A)BF3B)SiF4C)SF4D)XeF4 Pls answer it as soon as possible and also explain the reason.

Answer 1

SF4 is the answer. Since S has 6 valance electrons, two of them get bonded (4 electrons) while other 2 electrons remains as lone pair. According to VSEPR theory, It gains see saw-shape centered S. 
The shape is as shown in the figure.
Due to the presence of lone pairs and F ligands, It would have permanent dipole moment.

Answer 2

Answer:Correct Answer will be SF4.

Explanation:As it has a lone pair.