The calorie and the kilocalorie are units of which quantity?

• A. Temperature
• B. Energy
• C. Force
• D. Mass

Answer: (B)

Calories and kilocalories measure energy—the capacity to do work or produce heat. In nutrition, the energy in food is given in kilocalories, often called Calories with a capital C. One kilocalorie equals 1,000 small calories and about 4,184 joules. Temperature, on the other hand, is a measure of how hot or cold something is, not how much energy it contains or can deliver. Force describes a push or pull, and mass is the amount of matter in an object; neither of these quantities is what calories quantify. So calories and kilocalories are units of energy, used to express how much energy food can provide.