A scientist seals a sample of argon gas inside a rigid, constant-volume steel canister connected to a digital pressure sensor.
The canister is placed in a temperature-controlled bath and heated, and the pressure of the gas is recorded at different temperatures.
The results are plotted on the graph in the figure below.
Explain, in terms of the motion and collisions of gas particles, why the gas exerts a pressure on the inside of the canister, and why the pressure increases as the temperature is increased.