Photograph of the convection of liquidsApparatus:
rectangular glass tubing, coloured water, tongs, meaker burner, bbq lighter

Description:
With the tubing filled with water, hold one of the lower corners over the meaker burner. Introduce some food colouring to the tube - the convection of the liquid toward the heat source is visible due to the food colouring.

PIRA 4B20.10