How can you tell the overall polarity of a compound?

Question

I need to know if Silicon Tetrafluoride (SiF4) and Iodine Tetrafluoride (ICL4) are polar or non-polar overall.

Answer 1

SiF4 and ICl4 The molecules are non polar see my link.
The bounds SiF or ICl are polar but having a tetrahedral shape the symmetry makes the molecule in its whole non polar

Answer 2

First, draw the Lewis Structure for each of the compounds, and think about the shape of the molecules. Make sure you follow all the steps for drawing these structures so that you have correct structures. Next, determine whether the individual covalent bonds in the molecule are polar (In both these cases they are.) Finally, looking at the Lewis structure, determine whether all of the bonds are arranged in a way that their individual polarities will cancel each other out or not. In a compound like SiF4, I think you'll find that the compound has a tetrahedral shape, so the four polar bonds are all symmetrically arranged around the Si atom. So, this compound is not polar. In the second case, I think you'll find that there are one or more non-bonding pairs of electrons around the I atom, and that the bonds are not evenly distributed. So, this compound will be polar.