6
Fig. 6.1 shows a piece of apparatus used to show the transfer of thermal energy in liquids.
crystals
coloured water
glass
water
tube
heat
The glass tube is filled with cold water. Crystals that dissolve slowly are inserted into the bottom of
the tube. The water around the crystals becomes coloured.
When the glass tube is heated as shown in Fig. 6.1, the coloured water moves.
(a) (i) On Fig. 6.1, draw arrows indicating the direction of movement of the water in each section
of the tube.
(ii) State the name of this method of thermal energy transfer in the water.
(1)
FO
(b) Explain why the water moves in this way.