Aheating curve has two flat lines, or plateaus. what does the plateau at the higher temperature represent?
1. boiling of a liquid
2. melting of a solid
3. increase in temperature of a substance
4. decrease of a substance

The answer is B, the Melting point of a solid.

This is because it is a heating curve so the temperature is going to rise over time. The two plateaus mean that the element is changing phases and therefore the first plateau is the melting point because it goes from cold to hot.

Explanation:

Melting of a Solid

melting of a solid

Explanation:

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answer; protein;