What three things from outside a plant are needed for photosynthesis to occur?
There are three things outside of a plant that are needed for photosynthesis to occur. They are light energy, water, and carbon dioxide.
The science of Photosynthesis is made up of chemical reactants and products. Photosynthesis then has an equation, all the same. 6CO2 + 6H2O + Energy -> C6H12O6 + 6O2 Reactants Products The reactants being the ingredients. The products being the reaction, or product of mixing the reactants. Therefore, the things needed are the reactants. 6CO2 being Carbon Dioxide and 6H2O being Water. In reality, there are only two things needed. Carbon Dioxide and Water.
Water is needed for all living things, so plants aswell. Carbon Dioxide is like the plants Oxygen. But, for photosynthesis to occur, the plant needs to have a green surface(chlorophylls) and sunlight. Sunlight is needed because for every reaction, you need and activation energy. This time it's light. :)