Dark Stool: If your stool is black or bright red in color, it can mean that you are bleeding internally, as a possible result of an ulcer or cancer, and warrants a call to your doctor even if you think it could be hemorrhoids, or tiny tears in the anal tissue, due to constipation and straining.
The chemical reaction in which high molecular mass molecules are formed from monomers is known as polymerization. There are two basic types of polymerization, chain-reaction (or addition) and step-reaction (or condensation) polymerization.
The ability for molecules to form long chains is a vital to producing polymers. Consider the material polyethylene, which is made from ethane gas, C 2 H 6. Ethane gas has a two carbon atoms in the chain and each of the two carbon atoms share two valence electrons with the other.