CF4 is polar bond or not?

The answer is 4.

F atom is more electronegative than C atom. In C-F bond, F has a higher power to attract the electron cloud of the bond pair electrons, and thus the centre of negative charge shifts to the F atoms, and the centre of the positive charge is closer to the C atom. In other words, C-F is a polar bond. (Each C-F bond has a non-zero dipole moment.)

In CF4, there are four C-F bonds. The C atom in CF4 is sp3 hybridized, the four polar C-F bonds are arranged in tetrahedral regularly. Therefore, the dipole moments of the four C-F bonds cancel each other. This leads to no net dipole moment. (More precisely speaking, the net dipole moment is zero.)

=