It was an atom. It was a mixture. It was an element. It was a compound.
I gave my students this multiple choice question: During a lab investigation a scientist heats a solid substance. The scientist observes that the solid has two different melting points. The scientist is able to separate the two resulting liquids. Which statement best classifies the original solid substance?

Only one answer is correct among these 4 choices:
- It was an atom.
- It was a mixture.
- It was an element.
- It was a compound.

Could you tell me which one is correct?

It was a mixture.