expanding and compressing gases.

Question 1

what is the relationship between pressure and volume and what law tells us this?

Answer 1

Boyle’s law.
FX a constant mass of a gas at a constant temperature.
PV= constant.

Question 2

what does Boyle’s law tells us?

Answer 2

fixed mass of gas so number of particles is constant.
gas is at the same temperature so the average speed the particles move at it constant.
volume is smaller there will be more frequent collisions with the wall so the pressure is greater.
volume is larger there will be less frequent collisions with the wall so the pressure is lower.