Which of the following describes specific heat capacity?

Specific heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of a substance by a certain amount, typically 1°C or 1 K. This concept is significant in understanding how different materials absorb and retain heat.

When considering option A, it accurately reflects the definition of specific heat capacity: it specifically mentions "1 kg of a substance" and "by 1°C," which aligns perfectly with the accepted scientific definition. This is crucial for calculations involving energy transfer and temperature changes in various physical systems.

The other options relate to different thermal processes. They describe phenomena involving phase changes or energy exchange in different contexts, such as freezing or evaporating substances, but do not pertain to the specific definition of how much energy is required to raise the temperature of a given mass of a material.