Polarity of water
... oxygen’s need of 2 electrons. Each hydrogen atom shares one electron with the oxygen atom therefore they have a positive charge and the oxygen atom has a negative electronegativity charge because it receives 2 electrons. Therefore, the top half of the water molecule has a negative charge and the bottom half has a positive charge, so each end is a different charge, a characteristic of a polar substance. Because the ends have different charges they are attracted to each other and bond to each other: Shown above is 3 water molecules bonded, the 2 negatively charged hydrogen atoms are attracted to the negatively charged oxygen atom of another molecule which causes them to attract and bond. The molecules stick to one another, they are cohesive, another characteristic of a polar substance (2 down, 1 to go). If a solid substance is negatively charged then the 2 hydrogen molecules are attracted to it and they bond with the substance. If the solid is positively charged then it attracted to the oxygen atom and it bonds with that, either way all solids bond, or stick, with water. This is proof of the last characteristic of a polar substance, being adhesive. Now you can what makes water a polar substance. Why is the water molecule bent? If the shape of the water molecule was straightened out it would look something like this: Here you can see that there is no real top half or bottom half, there is three sections. The sides of the molecule are not oppositely charged which already makes it not polar, but also other water molecules cannot interlock with this straightened molecule. If they can’t bond to each other than they aren’t cohesive, and if they aren’t cohesive then the molecules must not be polar. Because they do not have oppositely charged ends they also do not attract well with all solids this molecule may bond with some negatively charged solids, but not all and not all means not adhesive. It must be adhesive to be polar, so this straightened molecule is not adhesive. It is very evident that water’s molecular sh...