What is specific heat defined as?

Specific heat is defined as the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius (or one Kelvin). This definition is essential in the study of thermodynamics and heat transfer, as it helps quantify how much energy is needed to change the temperature of a material. Different substances have different specific heat capacities, which means they will require varying amounts of energy to achieve the same temperature change.

The concept of specific heat is crucial for understanding processes involving heating and cooling, such as those that occur in refrigeration systems. It allows engineers and technicians to calculate how much energy is necessary to achieve desired temperature changes in various components.

The other options refer to different thermal properties but do not accurately define specific heat. For instance, heat per unit volume relates to density and thermal properties but does not consider mass. Heat needed for a phase change pertains to latent heat, which is involved when a substance transitions between solid, liquid, and gas states without a temperature change. Heat that is felt but not measured does not align with any specific thermal property and lacks scientific definition in the context of heat transfer.