What is the approximate temperature in Kelvin at which water boils?

The boiling point of water is typically defined as 100 degrees Celsius at standard atmospheric pressure, which corresponds to an approximate temperature of 373.15 Kelvin. The Kelvin scale is an absolute temperature scale, starting from absolute zero, where 0 K is equivalent to -273.15 degrees Celsius. To convert Celsius to Kelvin, you add 273.15 to the Celsius temperature. Therefore, when you convert the boiling point of water (100 degrees Celsius) to Kelvin, you get:

100 + 273.15 = 373.15 K.

This makes 373.15 K the correct choice, as it accurately represents the temperature at which water transitions from liquid to gas under standard conditions.