What is the temperature equivalent of absolute zero?

Absolute zero is defined as the temperature at which all molecular motion theoretically stops. It is a fundamental concept in thermodynamics and represents the lower limit of the thermodynamic temperature scale. In Celsius, absolute zero is exactly -273.15°C, which is often rounded to -273°C for simplicity in many contexts.

This temperature is significant because it conveys the idea that it is theoretically impossible to cool any substance to a temperature lower than this point. As such, -273°C is recognized universally as absolute zero in scientific literature, making it the correct answer to the question. The importance of understanding this concept lies in its implications for the behavior of matter at extremely low temperatures, including phenomena such as superconductivity and superfluidity.