Final answer:
When photons strike chlorophyll, they energize the electrons and cause them to become excited. The excited electrons play a crucial role in powering the biochemical reactions of photosynthesis.
Step-by-step explanation:
When light strikes chlorophyll, it energizes electrons within the molecule, causing them to jump to higher energy levels. These excited electrons are said to be 'excited.' The energy captured by chlorophyll is eventually used to power the biochemical reactions in photosynthesis, including the splitting of water molecules and the production of glucose.