Compounds are made up of 2 or more elements and they are all chemically bonded. The properties of a compound are different from the elements that make it up. Compounds can be broken back into elements by chemical reaction, exposure to light, etc. Compounds can be separated only chemically, not by physical means The mass of the compound is determined by the mass of the elements that make it up. When compounds are formed heat and light is given out or absorbed.
