Plants release oxygen during photosynthesis because they use sunlight to convert carbon dioxide into oxygen and glucose. The chemical equation for photosynthesis is:
6CO2 + 6H2O + sunlight → C6H12O6 + 6O2
In this equation, carbon dioxide (CO2) and water (H2O) are the reactants, and glucose (C6H12O6) and oxygen (O2) are the products.
During photosynthesis, plants take in CO2 from the air and water from the soil. They use the energy from sunlight to split the water molecules into hydrogen and oxygen. The hydrogen is used to combine with CO2 to form glucose, and the oxygen is released into the air.
The amount of oxygen released by plants depends on the amount of CO2 they take in and the amount of sunlight they receive. In general, plants release more oxygen during the day when there is more sunlight available.
The oxygen released by plants is essential for life on Earth. Animals and humans need oxygen to breathe, and plants need oxygen to produce their food. The oxygen cycle is a process by which oxygen is released by plants during photosynthesis and then used by animals and humans during respiration. This cycle helps to keep the amount of oxygen in the atmosphere at a constant level.
The image you sent me is a picture of the “Why do people logo”. This logo is used by the Why Do People organization, which is a non-profit organization that promotes science education. The logo is a stylized representation of a plant, and the question “Why do people?” is a reference to the fact that plants are essential for life on Earth.