Why does the temperature remain constant during the melting of ice even though heat is supplied?

 

When ice melts, heat energy supplied is used to break the intermolecular bonds between water molecules rather than raising the temperature. This energy is called latent heat of fusion. It allows the solid-state (ice) to convert into liquid (water) without any change in temperature. During this process, both ice and water coexist at 0°C. Only after all ice has melted does the temperature of water start to rise.

This explains why adding heat doesn’t always raise temperature—it can instead change the state of matter. Such processes are crucial in understanding thermal physics and real-life examples like ice melting in drinks.