Describe why atmospheric pressure decreases as height above Earth's surface increases Explain your answer using Atmospheric pressure (physics only) and collision.

Atmospheric pressure decreases with height because there are fewer air particles above a given surface as altitude increases. With less weight of air above, the force exerted by air particles on surfaces decreases, resulting in lower pressure.

A strong answer should address (Physics only) Use particle ideas to explain pressure from collisions with surfaces directly. Use the context of Atmospheric pressure (physics only) within Pressure and pressure differences in fluids (physics only), then state the relevant forces or motion reasoning with units where needed. The answer is correct when it names the key physics quantity, keeps force and pressure distinct, and links the conclusion back to the approved learning objective.