1. Absorption:

* Chlorophyll's Role: The primary pigment responsible for capturing light energy is chlorophyll. It absorbs light primarily in the blue and red regions of the spectrum, reflecting green light (which is why leaves appear green).

* Energy Transfer: When a photon of the right wavelength hits a chlorophyll molecule, it excites an electron to a higher energy level. This energy is then transferred to other molecules within the chloroplast, specifically to reaction centers within photosystems.

2. Photosynthesis:

* Light-Dependent Reactions: The absorbed energy powers a series of reactions called the light-dependent reactions. These reactions create ATP (adenosine triphosphate), a molecule that stores energy, and NADPH (nicotinamide adenine dinucleotide phosphate), a carrier of electrons.

* Calvin Cycle (Light-Independent Reactions): ATP and NADPH are then used in the Calvin cycle, a series of reactions that convert carbon dioxide from the atmosphere into sugar. This sugar is the leaf's source of energy and building blocks for growth.

3. Other Possibilities:

* Reflection: Some photons, particularly those in the green spectrum, are reflected by the leaf, contributing to its color.

* Transmission: A small amount of light can pass through the leaf, especially if it's thin or young.

* Heat: A portion of the absorbed energy is released as heat, contributing to the leaf's temperature.

In Summary:

When a photon hits a leaf, it is primarily absorbed by chlorophyll, triggering the process of photosynthesis. This energy is used to create sugars that fuel the plant's growth. A small amount of light may be reflected or transmitted, and some energy is released as heat.