What is defined as the quantity of heat required to raise the temperature of 1 gram of water through 1 degree on the Celsius scale?

The quantity of heat required to raise the temperature of 1 gram of water by 1 degree Celsius is defined as one calorie. This measurement is fundamental in thermodynamics and energy transfer, especially in contexts involving heat and temperature changes in water. The calorie is a standard unit in nutrition as well, often referred to when discussing food energy.

In contrast, a British thermal unit (BTU) is larger and is the amount of heat required to raise the temperature of 1 pound of water by 1 degree Fahrenheit, which is not applicable to this specific question about grams and Celsius. The joule is a unit of energy in the International System of Units and is defined differently from the calorie. A kilocalorie, which is equal to 1,000 calories, is also not relevant for the measurement specified in the question since it concerns the temperature increase of 1 gram of water, not a larger quantity.