Specific heat is defined as what?

• A. The amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius
• B. The energy transferred between objects at different temperatures
• C. The total kinetic energy of all molecules
• D. The rate at which heat is transferred

Answer: (A)

Specific heat tells you how much energy a substance needs to absorb (or release) to change its temperature, per unit mass, for a given temperature change. The definition described—that it is the energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius—embodies that idea, and its units (Joules per gram per degree Celsius or J/(g·°C)) reflect energy per unit mass per temperature change. For example, water has a relatively high specific heat, about 4.18 J/(g·°C), so it takes roughly 4.18 joules to raise 1 gram of water by 1°C. The other statements refer to heat transfer between objects, total kinetic energy of molecules, or the rate of energy transfer, none of which define the material’s capacity to change temperature per unit mass.