When water is heated at its boiling point or melting point, its temperature does not change.
a) What is meant by boiling point and melting point?
b) What are the boiling and freezing points of water?
c) Why is there no change in temperature?

A. The temperature at which a liquid boils at normal atmospheric pressure is called its boiling point.
The temperature of a liquid at which it freezes to solid at normal atmospheric pressure is called its freezing point.
B. 100°C, 0°C.
C. Once water starts boiling, the temperature will not change because all the heat supplied is utilized for the change of state. So the temperature does not vary.