General Knowledge
What is the freezing and boiling range of water in Celsius?
- 0 to 100
- 32 to 212
- 0 to 212
The answer is 0 to 100. The Fahrenheit figures are 32 and 212.
Zero to a hundred, which is the entire design of the scale rather than a discovery about water. Anders Celsius picked two reproducible points and divided the gap into a hundred parts - and originally had them the other way round, with zero for boiling.
Neither point is fixed in the way people assume. Both depend on pressure. On top of Everest water boils at about 70 degrees, which is why food will not cook properly at altitude, and a pressure cooker works by going the other way, holding the water liquid past 100 so the food cooks faster and hotter.
The scientific definition has since moved out from under both. The kelvin is now defined by the Boltzmann constant, a fixed number relating temperature to energy, so the modern scale does not depend on water at all - and as a result the boiling point of water is no longer exactly 100 degrees but a measured quantity that lands a fraction below. The definition and the schoolroom fact have quietly parted company.