What does specific heat (Cp) measure in a substance?

Specific heat (Cp) measures the amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius (or one Kelvin). This definition is pivotal in understanding how different materials respond to heat. The specific heat capacity explains why some substances heat up more quickly or hold onto heat differently than others, which is critical in various applications such as cooking, climate science, and thermodynamics.

Understanding specific heat allows us to predict temperature changes in substances when they absorb or release heat, making it a fundamental concept in fields like chemistry and physics. The other options, while related to heat and energy, do not accurately define the concept of specific heat.