Here's why:

* Photosynthesis Equation: The basic equation for photosynthesis is:

* 6CO2 + 6H2O + light energy → C6H12O6 + 6O2

* This means that carbon dioxide (CO2) and water (H2O) are used in the presence of light energy to produce glucose (C6H12O6) and oxygen (O2).

* Oxygen Release: During the light-dependent reactions of photosynthesis, water molecules are split, and the electrons from the water molecules are used to power the process. This splitting of water also releases oxygen as a byproduct.

* Significance: The oxygen produced by photosynthesis is crucial for life on Earth. It is used by almost all living organisms for respiration, a process that releases energy from food.