Answer:
boils
Explanation:
Vapour pressure of the liquid determines the temperature at which a liquid will boil. When water boils the pressure of the gas above it becomes equal to the vapour pressure of the liquid. This causes the inter-molecular bonds of water to break down and the water starts to evaporate. Water boils at 100°C at sea level however if you were to reach a higher altitude water would boil at a lower temperature as the air pressure will be lower.
