What is a common unit for specific heat capacity in the metric system?

• A. J/(g·°C)
• B. J/(kg·K)
• C. J/(m·s^2)
• D. W

Answer: (A)

Specific heat capacity tells us how much energy is needed to raise the temperature of a given amount of substance by one degree. In the metric system, a very common way to express this is energy per unit mass per degree temperature change, so using grams for mass and degrees Celsius for the temperature difference makes sense. Since a change of 1 degree Celsius is the same as a change of 1 kelvin, the unit joules per gram per degree Celsius (J/(g·°C)) is practical and widely used in labs and textbooks. The alternative J/(kg·K) is the SI base-unit form, and while correct, the question reflects a common metric-context unit, which is J/(g·°C). The other options aren’t appropriate for specific heat capacity: joules per meter per second squared isn’t a standard heat-capacity unit, and watt denotes power, not energy per temperature change.