It takes a shorter time for a liquid to boil at the top of a mountain than at the base because at the top, the
Answer Details
The correct answer is "pressure is lower." When you climb up a mountain, you go to a higher altitude where atmospheric pressure decreases. Since boiling occurs when the vapor pressure of the liquid becomes equal to the atmospheric pressure above it, when the atmospheric pressure is lower, the liquid boils at a lower temperature. This is because less heat is required to convert the liquid into vapor when the atmospheric pressure is low. Therefore, liquids boil at a lower temperature at higher altitudes because the pressure there is lower.