What is the balanced chemical equation for photosynthesis?

• A. 6CO2 + 6H2O -> C6H12O6 + 6O2
• B. CO2 + H2O -> CH2O
• C. 6O2 + C6H12O6 -> CO2 + 6H2O
• D. 2CO2 + 2H2O -> C2H4O2

Answer: (A)

Photosynthesis uses light energy to convert carbon dioxide and water into glucose and oxygen. The balanced equation shows six carbon dioxide molecules reacting with six water molecules to produce one glucose molecule and six oxygen molecules. This balance makes sense when you check atoms: six CO2 provides six carbons, which go into C6H12O6; six H2O provides twelve hydrogens, matching the twelve hydrogens in glucose; and the total oxygens on the left (from CO2 and H2O) equal the total on the right (six in glucose and twelve in O2). Other shown options either don’t conserve atoms or depict a process or a product that isn’t what photosynthesis yields, so they aren’t the correct representation.