Question

What is atmospheric pressure? Why does it decrease as we go higher?​

Answer 1

Pressure with Height: pressure decreases with increasing altitude. The pressure at any level in the atmosphere may be interpreted as the total weight of the air above a unit area at any elevation. At higher elevations, there are fewer air molecules above a given surface than a similar surface at lower levels.

Answer 2

Answer:

Atmospheric pressure is the pressure exerted by the weight of the atmosphere, which at sea level has a mean value of 101,325 pascals (roughly 14.6959 pounds per square inch).

Air molecules colliding with a surface cause atmospheric pressure. ... Atmospheric pressure decreases as the height of a surface above ground level increases. This is because, as the altitude increases: the number of air molecules decreases.