You are high up in the mountains and boil water to make some tea However, when you drink your tea, it is not as hot as it should be. You try again and again, but the water is just not hot enough to make a hot cup of tea. Which is the best explanation for this result? High in the mountains, the air pressure is significantly less than 1 atm, so the boiling point of water is much lower than at sea level.

The air pressure is significantly less than 1 atm, so the boiling point of water is much lower than at sea level.

Explanation:

This has to do with Gay Lussac's Law (a.k.a pressure law) which in essence means that when pressure goes up, temperature goes up and when pressure decreases, temperature decreases. This is why when the air pressure is signifcantly less than 1 atm (the pressure at sea level), the boiling point of water is much lower than at sea level.