Why does it take less energy to boil water on a mountain then at sea level

When pressure decreases, the boiling point also decreases. There is less pressure on a mountain then there is at sea level, so the water's boiling point should decrease on the top of a mountain. Because the boiling point decreases, it would take less energy(heat) to make the water boil.

I hope this helps. :)

distance, luminosity, brightness, radius, chemical composition, and temperature