Theory: answer each printed part. For drawings, upload a clear photo of your sketch on the supplied figure; show working and units for calculations.
Fig. 5.1 shows the particles (molecules) in a sample of liquid water.
(a)Explain, using ideas about particles, why liquids expand more than solids for the same temperature rise.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[2 marks]
(b)(i)The boiling point of water is 100 °C. State the boiling point of water on the Kelvin scale of temperature. Give your answer in K.
Answer guidance
State A short answer. No explanation is needed, and adding one cannot earn extra marks.
[1 mark]
(b)(ii)The boiling point of water is 100 °C. The temperature remains constant as water turns from liquid to gas at the boiling point. Explain, in terms of particles, why energy must be provided even though the temperature stays constant.
Answer guidance
Explain Give reasons, not just what happens. Each distinct reason is usually worth a mark.
[1 mark]
(c)An electric heater is used to heat a sample of metal, as shown in Fig. 5.2. There is no thermal energy transferred from the metal to the surroundings during the heating. The metal has a mass of 200 g and is initially at 15 °C. The heater is switched on for 2.0 minutes and then switched off. The maximum temperature reached by the metal is 40 °C. The power of the heater is 20 W. Calculate the specific heat capacity of the metal. Show your working. Give your answer in J/(g °C).
Answer guidance
Show The result is given, so every step of the reasoning is what earns the marks.
[3 marks]
5054/21/M/J/23Cambridge O Level Physics 5054 · May/June 2023 · Paper 2 variant 1 · Question 5