Here's a breakdown:

* Light energy from the sun is absorbed by chlorophyll, a pigment in plants.

* This light energy is used to split water molecules, releasing oxygen as a byproduct.

* The energy from the splitting of water is then used to convert carbon dioxide from the air into glucose.

* Glucose is a sugar that stores the chemical energy captured from sunlight.

So, in summary, light energy is the primary source of energy that is converted into chemical energy (glucose) during photosynthesis.