What is the standard photosynthesis equation in symbols and words?

• A. 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2
• B. 6 O2 + 6 H2O + light energy → C6H12O6 + 6 CO2
• C. CO2 + H2O → CH4
• D. C6H12O6 + O2 → CO2 + H2O

Answer: (A)

Photosynthesis uses light energy to convert carbon dioxide and water into glucose and oxygen. The standard equation in symbols shows the inputs on one side and the outputs on the other, balancing each type of atom. The usual form is 6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2, which in words is carbon dioxide plus water plus light energy yields glucose and oxygen. This version is correct because it accurately reflects what plants build (glucose) and what they release (oxygen) and it also balances atoms: six carbons, twelve hydrogens, and eighteen oxygens on both sides. The other options describe different processes or incorrect reactants/products—for example, producing methane or showing respiration, which is the breakdown of glucose, not its creation.