Physics 0625 · IGCSE · Thermal properties and temperature
Thermal properties and temperature — practice question
A test-tube holding solid wax is immersed in a beaker of very hot water for several minutes, and the wax turns into a liquid.
(a)[2]
State, at the molecular level, how a solid is different from a liquid.
(b)[1]
Explain, in molecular terms, why thermal energy has to be supplied for a solid to change into a liquid.
(c(i))[1]
Using Fig. 3.2, find the melting point of the wax.
(c(ii))[4]
From Fig. 3.2, determine the rate at which internal energy is lost by the wax as it solidifies. Give your answer in J/min.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Any two from: molecules in ordered positions / ordered arrangement / fixed shape; molecules not free to move around / fixed positions / only vibrate; molecules tightly packed / smaller separation; stronger intermolecular forces” …