The temperature at which any material changes its phase from liquid to vapour is called ____.
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Boiling point
The boiling point of a liquid is the temperature at which it changes into vapour throughout its mass, at a given pressure. At normal atmospheric pressure, pure water boils at 100°C; the temperature then stays fixed until all the liquid has turned into vapour, because the heat supplied is used to change the state.
The question asks for a temperature. Vaporisation is the name of the change from liquid to vapour itself, not of the temperature at which it takes place.