Here's how it works:

* Photosynthesis: Plants use a process called photosynthesis to capture light energy from the sun.

* Chlorophyll: Chlorophyll, a green pigment found in plant cells, absorbs sunlight.

* Chemical Energy: This light energy is used to convert carbon dioxide (CO2) and water (H2O) into glucose (a sugar) and oxygen (O2). Glucose is a form of chemical energy that plants can use for growth and other life processes.

So, the answer is light energy.