How is 'specific heat capacity' defined?

Specific heat capacity is defined as the amount of heat energy required to raise the temperature of one kilogram of a substance by one degree Celsius. This concept is crucial in thermodynamics and materials science, as it quantifies how much energy a material can store or release during temperature changes.

When a material absorbs heat, its temperature increases, and the specific heat capacity indicates how much energy is necessary for that temperature increase. Each substance has its own specific heat capacity, which is influenced by its molecular structure and phase.

In contrast, the other options relate to different thermal processes. The first option refers to the energy required for a phase change involving water; the third option pertains to the total energy content of a gas, which can vary with temperature and pressure; and the fourth option addresses the phase change from solid to liquid, which involves latent heat, not specific heat capacity. Understanding the specific heat capacity is essential for applications in various engineering fields, such as designing heating or cooling systems, where specific thermal properties of materials are critical for efficiency and effectiveness.