Is SiF4 Polar or Nonpolar?

Answer: SiF4 is a nonpolar molecule because the fluorine's are arranged around the central silicon atom in a tetrahedral molecule with all of the regions of negative charge cancelling each other out. 

Although the bonds within the molecule are polar covalent due to the great difference in electronegativity between fluorine (3.98) and silicon (1.90), the arrangement of the molecule disperses that charge within it pretty equally so that no negative dipoles are created in the process. Due to the presence of many fluorine's pulling electrons away from the center of the molecule, the structure as a whole is determined to be "electron-deficient" when compared to other molecules. This means it tends to pull in other charges and typically forms Hexafluorosilicic acid naturally, combining with two extra hydrogen atoms.

The way SiF4 is configured is very similar to the way methane's four hydrogen's encapsulate its central carbon. In fact, both silicon and carbon are part of the same group (Group 14 also known as the "carbon group") and therefore have very similar bonding properties, being capable of forming four bonds which is rare among elements with such a low atomic number. Feel free to learn more about either the Lewis Dot Structure for CH4 or the Polarity of CH4.

SiF4 Ball and Stick Model. Created with MolView.

Where is SiF4 found in nature?

Volcanic fumes typically produce several tonnes of SiF4 during eruption.