Guess the Boiling Point of Liquid Nitrogen

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You can probably look up the boiling point of liquid N₂, but if you want to try to guess consider the following game.

• At 0 ^oF, N₂ is a gas. If it weren't, liquid N₂ would rain down any time the atmospheric temperature dropped below 0 ^oF.
• Absolute zero is the temperature reached by all substances if all heat were removed. If all heat were removed, there would be one and only one state of matter--a solid. Recall that one must add heat to convert a solid to a liquid and add more heat to convert to liquid to a gas. If you remove all heat, all substance would become solids! Since liquid N₂ is not solid, the boiling point must be greater than -459 ^oF. The boiling point must lie between 0 and -459 ^oF.

Pick a number between and ^oF. Be sure to include a sign on your guess.

Guess: ^oF. ; Feedback: than

Comment on this skill: This skill is really a math skill called a binary search. Any time you can answer the question, "Is the value guessed too big? or too small?"; "Is the value too hot? or too cold?", you can get as close to the correct answer as you want. It is called a binary search because the quickest set of guesses to the correct answer is to divide the interval which remains in half for each new guess. "Bi" as in bicycle means 2; divide the interval by 2 each time.

How could the liquid N₂ itself answer the question, "too hot? or too cold?"

If you place an object into liquid N₂ which is too hot, it would boil. If you place an object into the liquid N₂ that is too cold, it would not boil.