Polar and non-polar molecules
A molecule is classified as a polar moleculewhen the arrangement of the atoms is such that one end of the molecule has a positive electrical charge and the other end has a negative charge. A polar molecule forms when an atom of high electronegativity bonds with a less electronegative atom. A polar molecule has electrical poles.
Water is a polar molecule. Ammonia, Sulfur Dioxide, and Hydrogen Sulfide are case in point of polar molecules of materials, which are gases under standard conditions.
Conversely, a non-polar molecule does not have electrical poles.The electrons are distributed more equally. Therefore, a non-polar molecule does not have a profusion of charges at the opposite ends. The majority of hydrocarbon liquids are non-polar molecules. An example of this is gasoline. Examples of non-polar molecule gases are Helium, Hydrogen, nitrogen, and methane among others. In addition,oil is a non-polar molecule.
Therefore,a molecule in which the bond dipoles present do not cancel each other out is a polar molecule. A non-polar molecule, in essence, is whenthe charges all cancel each other out.Non-polar molecules do not have charges at their ends.