Why does water boil at a lower temperature at high-altitude locations, such as near the summit of a tall mountain, compared to sea level?

Explanation

Water boils at a lower temperature at high altitudes because atmospheric pressure decreases as elevation increases, and a liquid boils when its vapor pressure equals the surrounding atmospheric pressure, which happens at a lower temperature when that surrounding pressure is reduced. This is why food, particularly items like rice or beans that require prolonged boiling, can take noticeably longer to fully cook at high-altitude locations, even though the water is still visibly boiling. This is also part of why pressure cookers are especially useful for cooking effectively at high altitudes. Explore more Everyday Science MCQs on mcqstutor to keep practicing.