Pigment is a molecule that absorbs light
-Sasha Muy :)
That pigment is called clorophyl.
The leaves are full of chloroplasts which contain the pigment chlorophyll. Green is the light wave reflected by this pigment.
The green pigment in plants associated with photosynthesis is chlorophyll. Chlorophyll is responsible for capturing light energy from the sun and converting it into chemical energy through the process of photosynthesis.