The original substances had different densities. The contents of the beaker reacted to form a new substance. The original substances had a greater mass than the contents of the beaker. The contents of the beaker can be easily separated into the original substances.
I gave my students this multiple choice question: Each student in Ms. Jordan's science class was given a beaker containing several substances that had been stirred thoroughly. Maxwell must classify the contents of his beaker as either a compound or a mixture. Which of the following would indicate that the beaker contains a mixture?

Only one answer is correct among these 4 choices:
- The original substances had different densities.
- The contents of the beaker reacted to form a new substance.
- The original substances had a greater mass than the contents of the beaker.
- The contents of the beaker can be easily separated into the original substances.

Could you tell me which one is correct?

The contents of the beaker can be easily separated into the original substances.