How is a compound different from a mixture? *

a. mixtures are created through physical changes; compounds are created through chemical reactions.
b. compounds are created through physical changes; mixtures are created through chemical reactions.
c. mixtures, on average, are heavier than compounds.
d. compounds, on average, are heavier than mixtures.

a.  mixtures are created through physical changes and compounds are created through chemical reactions

Explanation:

During a chemical reaction, matter cannot be created nor destroyed, matter can change form through physical and chemical changes, but through any of these changes, matter is conserved; even though the matter may change from one form to another, the same number of atoms exists before and after the change takes place.

Explanation: <3