The graph shows the change in temperature of a sample of water in a closed system as thermal energy is added over time. Temperature: -50oC; 0oC; 50oC; 100oC; 150oC;
Time: 10; 20; 30; 40; 50; 60;
What happens to the speed of the particles of the water undergoes a change of state?
A. it remains the same.
B. it increases gradually
C. it comes to a complete stop
D. it decreases gradually