SAT Subject Physics Practice Question 508: Answer and Explanation
9. The graph below shows a typical heat and temperature graph for a substance.
Which of the levels represents the solid phase of the substance?
A. Level A
B. Level B
C. Level C
D. Level D
E. Level E
Correct Answer: A
The correct answer is (A). During the time when the substance is at the part of the graph, it can either evaporate or condense. This entails a phase change, which is accomplished by the substance gaining energy.