Question

heated to its boiling point temperature. at its boiling point temperature, the addition of heat causes the liquid to transition to a gas at a constant temperature. once all the liquid has boiled, the sample continues to be heated (cautiously), causing the temperature of the gas to increase. this process is depicted in figure 1.
figure 1
there are five labeled points on the line of the graph in figure 1. what changes, in order, are observed in the sample of matter between point a and point c?
first the sample melts; then its temperature stabilizes; then it boils.
first the sample increases its temperature; then it melts; then its temperature increases.
first the sample increases its temperature; then it melts; then its temperature stabilizes.
first the sample increases its temperature; then it melts; then it stabilizes its temperature.

Explanation:

Step1: Analyze the graph segments

From point A to the start of the horizontal segment (melting phase): The temperature line is increasing, so the sample's temperature is rising.

Step2: Analyze the horizontal segment (melting)

The horizontal line (e.g., around point B) represents a phase change (melting) where temperature is constant while heat is absorbed to melt the solid.

Step3: Analyze from end of melting to point C

After the horizontal (melting) segment, the temperature line rises again, meaning the liquid’s temperature is increasing.

Answer:

First the sample increases its temperature; then it melts; then its temperature increases.