What is the Celsius equivalent of absolute zero on the Kelvin scale?

Absolute zero on the Kelvin scale is defined as 0 K. To convert this temperature to Celsius, you use the formula:

[ \text{Celsius} = \text{Kelvin} - 273.15 ]

Applying this formula:

[ 0 K - 273.15 = -273.15 °C ]

When considering standard rounding conventions, this can be approximated to -273°. Thus, the Celsius equivalent of absolute zero is -273°, making it the correct answer.

Understanding this underlines the relationship between the Kelvin and Celsius scales, where 0 K represents the lowest possible temperature, indicating no thermal energy. This foundational concept is critical in thermodynamics and various scientific disciplines.