Question

how to determine if a molecule is polar or non-polar? easiest and fastest way please?

Answer 1

Polar=One end is slightly negative and the other is slightly positive.
When polar molecules are placed between oppositely charged plates, they tend to become oriented with respect the positive and negative plates.

Answer 2

I would start by drawing the molecule and then show where there are charges. then if you notice that there is a significant difference in their position such that the positive charge is facing a specific side then it would be polar if not then it is not polar.

An other way would be by looking at the formula.
1. count how many valence electrons the center atom has.
2. see if all spaces are being used.
3. see if all the atoms that are connected to the central atom are the same. if so it is most likely non polar. (don't forget to check the charge.)
4. if the atoms connected to the central atom are different then I am unsure of a fast way to determine.

Hope this helps.

Answer 3

so for example, you're given an element - HCl (hydrochloric acid) how will you know what's the center atom?