What is the tripple point on a phase diagram?

The Triple point is the point where a substance can exist in equilibrium as a solid, liquid, and gas. Which occurs only at a certain pressure and temperature combination. Unfortunately it doesn't occur at atmospheric conditions.

Ithink this is what you meant. the temperature at which a liquid begins to boil is called the boiling point. the boiling point of water is 212°f or 100°c.  and at that point will start to turn into steam (gas)

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