Question

pure substance that is the more pure is
atom
elements
compounds
mixtures

Explanation:

An atom is the most basic unit of a chemical element. Elements are made of the same - type of atoms. Compounds are made of different elements chemically combined. Mixtures are physical combinations of substances. Since an atom is the fundamental and indivisible (in the context of chemical purity at this basic level) unit among these, it represents the purest form among the given options.

Answer:

atom