One regular calorie is equivalent to how many Joules?

A regular calorie, specifically referred to as the small calorie (cal), is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius. This unit of measurement is commonly used in chemistry and biology to quantify energy, especially in the context of nutrition and food energy.

The conversion factor between calories and Joules is a well-established scientific fact, with one calorie equal to approximately 4.184 Joules. This is derived from experiments that measure heat transfer in water, allowing scientists to relate thermal energy to mechanical energy. Therefore, the correct answer of 4.184 Joules accurately represents the energy equivalence of one calorie in the International System of Units (SI).

Understanding this conversion is vital in fields such as thermodynamics and nutrition, where energy calculations are frequently performed.