What defines a mixture?
A.
can be broken down into its basic substances through physical means
B.
described by a chemical formula
C.
cannot be broken down into simpler substances
D.
created through a chemical reaction
A. because a mixture can be physically separated by methods such as sieving, decantation, distillation, evaporation or filtering. For example a water+salt solution is a mixture and can be separated through evaporation.