Question

question 1
air pressure...(select all that apply)
a will decrease when molecules are added to a sealed container.
b is the force exerted on a surface by air molecules.
c is greater higher when less molecules strike a surface.
d gets less as you get higher in the atmosphere.

Explanation:

• According to the ideal - gas law ($PV = nRT$), adding molecules ($n$ increases) to a sealed container (constant $V$ and $T$) increases pressure, so A is incorrect.
• Air pressure is the force exerted by air molecules on a surface, so B is correct.
• Fewer molecules striking a surface means lower air pressure, not higher, so C is incorrect.
• As altitude increases in the atmosphere, the number of air molecules decreases, resulting in lower air pressure, so D is correct.

Answer:

B. is the force exerted on a surface by air molecules.
D. gets less as you get higher in the atmosphere.