A metal vessel, filled with hot water at 90°C, is placed on top of a wooden block at the centre of a large metal container. The metal container is filled with soil and covered with a wooden lid. A metal pin was attached to the metal container with candle wax. When the candle wax gets heated up, the pin falls. The experiment was repeated by replacing the soil with cold water and later with cotton wool.

Time taken for the pin to fall: soil 8 minutes; cotton wool 20 minutes; cold water 12 minutes.

1. aWhich of the materials is a poor insulator of heat? [1]
2. bExplain your answer. [1]
3. cState two processes through which heat reaches the candle wax. [2]
4. dThe inside wall of the metal container is painted white. How will this affect the time taken for the pin to fall off? [1]
5. eExplain why a wooden lid is used in the set-up. [2]

You'll mark your own answer against the marking guide when you hand it in.