1. The problem statement, all variables and given/known data I had an issue with a professor a while ago. A question was asked, "Why does water boil at 100°C?". What I believe was the targeted answer was something around "Hydrogen bonds." Hydrogen bonds are a valid answer, I believe also correct enough. For clarity purposes, I found some more correct answers, which I list below. I came here to know some more answers, if anyone finds more. That question is very vague, and allows more proper answers than what it is supposed to be. 2. Some valid solutions Because Celcius said so. Because room pressure is 1 atm. Hydrogen bonds. Because of the big electronegativity difference between hydrogen and oxygen. Because it has no strange compound mixed with.