Is XeF2 Polar or Nonpolar?

Answer: XeF2 is a nonpolar molecule due to the linear arrangement of the fluorine atoms around the central xenon atom. This results in the different pulls on the electrons of the central atom cancelling out and therefore there is no permanent dipole. 

Although this may seem counterintuitive since the central xenon atom has three lone pair of electrons, it is important to consider that those lone pairs are actually arranged in a trigonal planar orientation around the molecule. Please take a look at PF5 to see this trigonal planar + linear pattern visualized with fluorine atoms. In essence here we only have two fluorine atoms and the lone pairs replace the trigonal planar arrangement.

Therefore when you cut the "xenon" plane in half you find two lone pairs either above or below the plane and then the one remaining lone pair either above/below the plane depending on where the first two lone pairs appeared. The difference in these charges allow for XeF2 to form a crystal - matching up regions with two lone pairs with the corresponding region with one lone pair on another XeF2 atom. This crystal lattice is strengthened by the capacity for more powerful temporary bonds due to the large number of electrons within the structure (xenon itself has 54 electrons!).

However, due to the natural stability of noble gases, the molecule is very sensitive to energy input. Although it is stable in storage, any exposure to sunlight or moisture quickly decomposes the molecule. Within storage as mentioned before it forms a white brilliant crystalline solid.

XeF2 Ball and Stick Structure
XeF2 Ball and Stick Structure. Created with MolView.
How is XeF2 utilized in the real world? 

Due to the presence of fluorines and the capacity for XeF2 to give up those fluorines, it is often utilized as a chemical agent to add fluorines to a certain compound/molecule. It can also be utilized to manipulate/design tough silicon systems through the release of fluorine in order to manufacture specific electrical components.