Question

what are pure substances
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Answer 1

Answer:

A chemical substance is a form of matter having constant chemical composition and characteristic properties. Some references add that chemical substance cannot be separated into its constituent elements by physical separation methods, i.e., without breaking chemical bonds. 

Answer 2

Substances which are formed with same types of atoms or same types of molecules are called as pure substances.

Elements & Compounds are pure substances.

Elements are formed by same types of atoms and compounds are formed by same types of molecules.

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