Question

what happens to air pressure when you go up in the mountains

Answer 1

The air in the atmosphere presses down on you all the time. Therefore, as you go up in elevation, or height, air pressure decreases. For example, if you were at the top of a high mountain, you would have less air pushing down on you than you would if you were at sea level. Both air and water are fluids.
Hope this helps u

Answer 2

In air, pressure varies with height .Therefore, as you go up in elevation, the air pressure decreases. For example, if you were at the top of a high mountain, you would have less air pushing down on you than you would if you were at sea level.