9. The graph below is a heating curve for a pure substance. It shows how the temperature rises with time, when the solid is heated. (6 marks) 15 CTemperature 110°C sa SOUD RD B ↓ C Liquid Time gas E b a) What changes is taking place at point B and at point D? (2 marks) Ans: 1. B is starts melting 2. Dis starts bong b) What is the melting point of the substance? (1 mark) Ans: 18 15°C Page | 4​