Element
Some synonyms for pure substance could be chemical compound, element, or homogenous material.
Compounds and substances are practically synonyms; a compound or substance may be impure (contain impurities) or pure ( the impurities are only as traces or absent).
pure substance, propanone
pure
it is a pure substance.... not
Pure substance
Methane is a pure substance.
pure substance
pure substance
Pure Substance
A pure substance is classified by having a definite and constant composition. The substance can be either an element or a compound, but what makes the substance pure, is that it does not vary.
Neon is a pure substance. Elements and compounds are pure substances; mixtures are not.