Question

Which is the best interpretation of the two flat portions of the graph?
A. These show where kinetic energy is increasing.
B. These show where temperature is 0 C.
C. These show where thermal energy does not exist.
D. These show where changes of state are occurring.

Answers

GPT-4o mini
The best interpretation of the two flat portions of the graph is:

**D. These show where changes of state are occurring.**

In a temperature vs. heat added graph, the flat portions typically represent phases where a substance is undergoing a change of state, such as melting or boiling, during which the temperature remains constant until the phase change is complete.