Answer:
Chlorophyll
Explanation:
Photosynthesis is the process through which plant cells use carbon dioxide & water to create oxygen & energy rich organic compounds. They do so by converting sunlight ie light energy into chemical energy. This is possible due to presence of chlorophyll in them. Animals can't do so, as they dont have chlorophyll.
.3333333 as a repeating decimal
It allows you to determine the relation between the reactants and the products.