Fig. 3.1 shows gas at room temperature. The gas is trapped in a metal cylinder by a metal piston fixed in position. [Figure 3.1]

1. (a)Explain, in terms of electrons and the atoms of the metal, how thermal energy is transferred through the walls of the metal cylinder.[3]
2. (b)The piston is fixed in position so the pressure of the gas increases as the temperature of the gas increases.
3. (b)(i)State what happens to the motion of the particles of the gas as the temperature increases.[1]
4. (b)(ii)Explain, in terms of the particles of the gas, why the pressure the gas exerts on the walls of the metal cylinder increases as the temperature increases.[3]
5. (c)The gas in the cylinder reaches a temperature of 100 °C. The piston is released and moves to the right. The temperature remains at 100°C. The pressure of the gas now decreases.
6. (c)(i)Explain, in terms of the particles of the gas, why the pressure of the gas now decreases.[1]
7. (c)(ii)Eventually, the piston stops moving. Explain why.[2]

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