Plants may grow faster if they have more carbon dioxide.
Clear plastic bag
Indigestion tablets dissolve in water to form a
solution.
This solution slowly gives off carbon dioxide.
A student set up an investigation to see what
concentration of carbon dioxide is best for
increasing the growth of geranium plants.
Dish containing water
and one tablet
The student:
put a geranium plant in a clear plastic bag
put a dish containing water and one tablet in the bag and sealed the top of the bag.
The student:
set up 5 more experiments each with water and a different number of tablet and left all
the plants in a well-lit place for four weeks.
The student used a clear plastic bag, not a black plastic bag.
Explain why.