In the process of heating, a substance from a solid state passes into a liquid and then into a gaseous state.

In the process of heating, a substance from a solid state passes into a liquid and then into a gaseous state. The figure shows a graph of the dependence of the temperature of a substance on time. Which section of the graph corresponds to the process of heating a liquid?

to find out that the body is heating up, you need to look at the graph, if the line rises up, then the body heats up, if the line on the graph moves horizontally, then it either boils or melts. Likewise, the body cannot be heated above the boiling / melting point during melting / boiling.