what is the difference between a polar and non-polar substace?

Answer 1

In a polar substance (like water) each molecular has a "dipole moment" meaning that one end is slightly positive in charge, and the other negative. In non-polar substances, there is not a static distribution of charge across the molecule (like in a hydrocarbon such as butane). Polar molecules will dissolve usually in polar solvents and non-polar won't, and vice-versa (remember like dissolves like).

Answer 2

All atoms have both protons (+) and electrons (-). Molecules form when atoms (say, two hydrogen atoms and one oxygen atom), bond (either covalently or ionicly; ionic in the case of water). Polar molecules are usually formed by ionic (hydrogen) bonding. What this means, is that the atoms share electrons (-), but most of them migrate towards the two hydrogen atoms, bending the water molecule into the classic Mickey Mouse shape rather than just being a H-O-H stick. With the all the electrons at one end, only protons (+) are left at the other end with the oxygen atom and the resulting molecule looks basically (within the limits of typing) like this: (-)H-H-O(+) (although the H's aren't connected to each other, only to the oxygen). I hope you were able to make sense of all that in the end. Oh, wait, non-polar molecules, basically, don't do that. That's the best answer I have for that part of that question...

Answer 3

A polar molecule will have positive and negative charges at different point of the molecule. A non-polar substance does not.

An example of a polar substance is water. It has a negative charge at the O atom and positive charges at each of the two H atoms.

Answer 4

polar substances have a charge whether it be negative or positive and non polar substances do not