Is SF6 Ionic or Covalent?

Answer: SF6 (or sulfur hexafluoride) is a covalent compound because both sulfur and fluorine are nonmetal elements. This means that in their natural forms either S2 or F2 they are found as nonmetals. 

Furthermore, SF6 is in a gaseous state of standard temperature and pressure which contributes to the view that the compound contains covalent "sharing electron" bonds. The molecule due to the saturation of fluorines is electron-deficient and therefore readily undergoes many different kinds reactions. Since the structure is symmetrical in both the vertical and horizontal directions, all of the different charges along the molecule cancel out and it is determined to be nonpolar. SF6 therefore has poor solubility in water and high solubility in less polar/more nonpolar compounds.

As you would expect SF6 does not disassociated into ions when placed in water as many ionic compounds are bound to do (think about how NaCl splits into Na+ and Cl- ions when it enters water (H2O)). These properties are similar to other molecules saturated with fluorines including SF2 and SiF4 (learn about their polarities by clicking on the hyperlinks). SF6 exists because an expanded octet allowing for the d subshell to engage in bonding with different elements, thereby permitting the sulfur to have more than eight valence electrons.

SF6 Ball and Stick Structure
SF6 Ball and Stick Molecular Structure. Created with MolView.
How is SF6 commonly utilized in the world?

SF6 is commonly utilized as a tracer in the medical field and other varied applications. The reasons for this are twofold: SF6 can be easily detected at very low concentrations and SF6 exists at negligible concentrations within the atmosphere. This makes it ideal for tracing the movement of gaseous compounds through different spaces.