Polarity of Sulfur Hexafluoride (SF6)
In the sulfur hexafluoride (SF6) molecule, sulfur (S) occupies the central position as it is less electronegative than the surrounding fluorine (F). Sulfur has six electrons in its valence shell. Fluorine needs only one electron to complete its octet. Therefore, sulfur will share all six electrons with the fluorine atoms, resulting in six single covalent bonds. The fluorine atoms are placed symmetrically around sulfur, creating an octahedral structure.
The electronegativity of sulfur is 2.68, and that of chlorine is 3.98. A significant electronegativity difference (1.4) between the two atoms results in a polar S-F bond. The individual S-F dipole moments get canceled in the symmetric, octahedral SF6 molecule. In other words, the pull of electrons by fluorine on one side equals that on the other. Therefore, sulfur hexafluoride is a nonpolar molecule.