Is boiling basically a really high vapor pressure?
Not "really high" - just high enough.
From memory, boiling is the condition where the vapor pressure equals that of the atmospheric pressure.
External pressure (which doesn't have to mean atmospheric - think vacuum, distillation, think steam engine boiler). But you are mostly right, that's the definition.
Not sufficient. Boiling also requires that bubbles must actually be initiated inside liquids. Overheated liquids do not boil even if they are rapidly evaporating from free surface.
How does it matter for the definition?
Yes you are correct, I should have been more specific. It is indeed the external pressure, atmospheric pressure being a specific case.
My P-Chem text and Wikipedia both disagree with you. I see what you are getting at, but then would you not consider the freezing point of pure water 0 degrees C because it can be supercooled?
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