Can you determine polarity by looking at a Lewis formula or VSEPR theory shapes?
Yes, you can. There are two rules in determining polarity once you have the Lewis dot structure or the VSEPR shape. I. If all similar regions are not the same, the chemical species is polar unless symmetry takes preccedence. A general idea of the polarity direction (towards the negative region) may be obtained from electronegativity values and/or formal charge. II. If all similar regions are the same, the chemical species is nonpolar. Look on the website for additional examples. As a clarification for the symmetry part, it means that opposing ends of equal electronegativity cancel out.
