Answer: a mixture
Step-by-step 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 or physical reactions.Example: Copper
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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
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Mixture is a substance which has two or more components which do not combine chemically and do not have any fixed ratio in which they are present. It can be decomposed into simpler constituents using physical means. Example: Air