1. Year 8 Thermal Transfer Test
Mark Scheme /36

2. Question 1 /5 marks Hot oven 200oC Human Body Temp 37oC
Cold winter morning 2oC
Temperature of the sun’s surface 5500oC
Freezing point of water 0oC
Boiling point of water 100oC
A domestic freezer -20oC

3. Question 2 / 6 marks
a. b.
c. conduction occurs when particles collide / bump /hit (1)
Particles in solid are fixed (1)
Vibrations increase when solid is hot (1)
Gas particles further apart, collisions less likely (1)

4. Question 3 / 4 marks The heater warms the room by CONVECTION (1)
Particles speed up and spread out (expansion) and the air becomes less dense (1)
Warmer air rises, colder air falls creating convection current (1)
Heat is transferred upwards from the heater & around the room (1)

5. Question 4 / 5 marks Hot dish burning table top – conduction
Sea breeze – convection
Hot embers cooking a sausage - radiation (allow convection)
Heat from the sun – radiation
Cold feet when standing on tiled floor - conduction

6. Question 5 / 6 marks
Generally metals are better CONDUCTORS of heat than NON-METALS / GASES/LIQUIDS. Conduction occurs when two surfaces are in contact. The heat energy always flows from regions that are HOT / HIGH HEAT ENERGY to regions that are COLDER. Polystyrene and wool are good examples of insulators. This is because they contain lots of trapped AIR / GAS which is a POOR conductor.

7. Question 6 / 10 marks Base readings / control / worst case (1)
1.Roof with insulation & single glazed window
2. Window with double glazing and roof with no insulation. (2)
Graph – title, axes labelled & units (1)
Suitable scale (1)
Both line points plotted carefully (2)
Lines/ curve of best fit (1)
d. Line or curve of same shape above the other two lines and starting at 40oC (2)