Answer: e) all of these
Explanation:
Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Copper
Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: water [tex](H_2O)[/tex], carbon dioxide [tex](CO_2)[/tex]
Mixtures are not pure substances as they consist of elements and compounds combined physically and not in any fixed ratio. Example: Air
Thus all given substances are pure substances.
