B8 - Photosynthesis

Step 1

Place boiling tube 10cm away from an LED light source (DON’T RELEASE MUCH HEAT)

Step 2

Fill boiling tube with sodium hydrogen carbonate (PROVIDES PLANT WITH CARBON DIOXIDE) solution

Step 3

Put piece of pondweed in boiling tube with the cut at top and leave it for 5 mins to get used to the conditions in boiling tube

Step 4

Start stopwatch and count amount of bubbles produced in 1 min

Step 5

Repeat two more times and calculate mean number of bubbles produced in 1 min

Step 6

Do whole experiment again but with different distances (20cm/30cm/40cm)

Step 7

Plot graph of number of bubbles against distance in cm and it would show that if the distance is doubled, the number of bubbles produced per minute falls by a factor of 4