Is there really such a thing as a Neapolitan chord?
Yes, there is, and it adds a lot of variety into the music itself. Another way to write for a Neapolitan chord is a Flat-II chord that is in first-inversion. There are many uses for these chords, and once you know how to identify them, they are easily spotted.
How can I determine if a molecule is polar or non-polar?
There are many different ways to determine the polarity of a molecule. However, one of the best ways is to look for Carbon atoms. Also, long chains of carbon tend to mean that the molecule in question is non-polar. There is a lot more that goes into the polarity, but, a quick check is always to look at the elements involved.
Is grammar really that important to know?
It is extremely important to know. Without it, you are relying on a spell-check and grammar-check to make sure that you are being proper. It will look for general usage and make sure that words aren't spelled incorrectly. However, it will not understand context and there are often-times where context is everything for a word.