What quantity is measured directly to determine specific heat capacity?

To determine specific heat capacity, one must measure the temperature change of a substance directly. Specific heat capacity is defined as the amount of energy required to raise the temperature of a unit mass of a substance by one degree Celsius (or one Kelvin). Therefore, measuring the temperature change is crucial, as it provides data on how much the substance's temperature has increased after a known amount of energy has been added.

While the other options involve quantities relevant to the overall calculation, such as the mass and energy absorbed, they are not directly measured to find specific heat capacity. The specific heat capacity formula incorporates the mass and energy changes, but the key direct measurement needed for the calculation is the change in temperature. This fundamental relationship highlights why monitoring the temperature change is essential when estimating how much energy a substance can store without undergoing a phase change.