* "k" is not a standard unit of temperature. It's likely you're thinking of "K" which stands for Kelvin, the standard unit of temperature in the scientific community.
* Kelvin and Celsius are related but not directly interchangeable. Kelvin is an absolute temperature scale where 0K is absolute zero (the theoretical point where all molecular motion stops). Celsius is a relative scale where 0°C is the freezing point of water.
To convert Kelvin to Celsius, use this formula:
°C = K - 273.15
Therefore, to convert 200K to Celsius:
°C = 200 - 273.15 = -73.15°C
