| − | '''Carbon dioxide''' in an odorless, colorless [[gas]] formed by the [[combustion]] of [[hydrocarbon]]s, both nataurally, in the human body, and artificially, as fuel. It is one of the human body's major waste products, being excreted through exhalation. | + | '''Carbon dioxide''' in an odorless, colorless [[gas]] formed by the [[combustion]] of [[hydrocarbon]]s, both naturally, in the human body, and artificially, as fuel. It is one of the human body's major waste products, being excreted through exhalation. |