Physics 0625 · IGCSE · Kinetic particle model of matter
Kinetic particle model of matter — practice question
The class watches a demonstration on heat energy and states of matter. A substance is heated by the teacher. A heater delivers thermal energy at a constant rate. The students record the substance’s temperature each minute for 30 minutes. Fig. 4.1 presents the graph of their results. At point A, the substance is solid.
(a(i))[1]
Describe how the thermal energy input affects the substance in section AB of the graph.
(a(ii))[1]
Describe how the thermal energy input affects the substance in section BC of the graph.
(a(iii))[1]
Determine the temperature at which boiling happens for the substance.
(a(iv))[1]
Deduce the state of matter of the substance in section EF on the graph.
(b(i))[3]
Describe how evaporation occurs. Use your ideas about particles.
(b(ii))[1]
Describe another effect evaporation has on the water left in the puddle.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “temperature rises” …