Sara carries out an experiment to investigate the rate at which the leaves of a pond plant
produce bubbles of oxygen when exposed to different intensities of light.
The apparatus used is shown in Fig. 6.1.
The investigation is carried out in a dark laboratory. The only source of light is the lamp.
Sara changes the light intensity by placing the lamp at different distances from the plant each
time.
She records the number of bubbles of oxygen produced by the plant at each distance.
The results are shown in Table 6.1.
