What is the Kelvin value for the freezing point of water?

• A. 273 Kelvin
• B. 0 Kelvin
• C. 373 Kelvin
• D. 100 Kelvin

Answer: (A)

Kelvin is an absolute temperature scale where 0 K is absolute zero, and to convert from Celsius you add 273.15. Water freezes at 0 °C, so its freezing point in Kelvin is 0 + 273.15 ≈ 273.15 K. Rounding to the nearest whole kelvin gives 273 K, which matches the freezing point. The other values correspond to different extremes: 0 K is absolute zero, 373 K is the boiling point of water at one atmosphere, and 100 K is far below freezing. So 273 Kelvin best represents the freezing point.