Moving up and on! Two years after his ex-girlfriend Kristen Stewart cheated on him, Robert Pattinson showed that he was long over the scandal by laughing it off in an interview for the September 2014 issue of Esquire UK.
adjective, purer, purest. 1. free from anything of a different, inferior, or contaminating kind; free from extraneous matter: pure gold; pure water. 2. unmodified by an admixture; simple or homogeneous. 3. of unmixed descent or ancestry: a pure breed of dog.
Yes, in chemistry a pure substance means either an element or a compound. Thus, hydrogen, oxygen, sodium, iron, copper etc. are pure substances; and so are compounds such as water, sugar, ammonia, sodium chloride, methane, ethanol etc. A compound is composed of two or more elements combined in a fixed ratio by mass. Like an element, a compound also has a distinct chemical identity. A mixture is not a pure substance as it is a collection of two or more elements/compounds in varying ratio. Air, sea water, gasoline, vegetable oils, steel etc. are mixtures.