A method of analysis which the components of a chemical mixture can be separated, identified, or purified. The behavior of the earth's atmosphere to trap and hold heat near its surface, causing global warming. Once groundwater has been contaminated, it is nearly impossible to return it to its pure state. The main source of drinking water from wells and springs. H halogen A non-metallic element, such as fluorine, chlorine, bromine, iodine, or astatine.
Halogenated compounds are more likely to be toxic.
Contrast with dehalogenation . A waste may be hazardous because it is toxic, ignitable, corrosive, or dangerously reactive. Many heavy metals are toxic and since they do not easily break down, they can bioaccumulate in living organisms. Hydrocarbons are found primarily in petroleum, natural gas, and coal products. See also aromatic and chlorinated hydrocarbon .