Which term describes heat energy involved in phase changes rather than temperature change?

• A. Specific Heat
• B. Latent Heat
• C. Thermal Conductivity
• D. Sensible Heat

Answer: (B)

Heat energy that changes a substance’s state without raising its temperature is latent heat. When ice at 0°C melts, energy goes into breaking the solid’s structure so it becomes liquid, not into warming the temperature. The temperature stays at 0°C until all the ice has melted, and a similar idea happens when liquid water becomes steam at 100°C—the energy goes into changing the phase, not increasing temperature. This is different from sensible heat, which is the portion of heat that actually changes the temperature. Specific heat relates the amount of heat to a given temperature change in a particular phase, and thermal conductivity describes how readily a material conducts heat, not the energy involved in phase changes.