AP BIOLOGY

Detailed explanation-1: -When things are different at each end, we call them polar. Some molecules have positive and negative ends too, and when they do, we call them polar. If they don’t, we call them non-polar. Things that are polar can attract and repel each other (opposite charges attract, alike charges repel).

Detailed explanation-2: -A polar molecule is a molecule in which one end of the molecule is slightly positive, while the other end is slightly negative. A diatomic molecule that consists of a polar covalent bond, such as HF, is a polar molecule.

Detailed explanation-3: -The unequal sharing of electrons between the atoms and the unsymmetrical shape of the molecule means that a water molecule has two poles-a positive charge on the hydrogen pole (side) and a negative charge on the oxygen pole (side). We say that the water molecule is electrically polar.

Detailed explanation-4: -Polar molecules have a negative “end” and a positive “end.” They tend to associate because the positive end of one molecule attracts the negative end of another molecule.

Detailed explanation-5: -In a nonpolar molecule, there are no positive or negative poles formed in the molecule. Any charges are distributed evenly across the molecule. Nonpolar molecules are generally symmetrical, like the tetrahedral molecule carbon tetrachloride. Another example is boron trifluoride, which is trigonal planar.