Nitrogen fixation is a biological activity when nitrogen gas is the only nitrogen source present in the environment. Write a half-reaction equation that represents the synthesis of cellular material (represented by the chemical formula C5H7O2N ) when nitrogen gas is used as the nitrogen source. 1.Identify products and reactants 2. Balance other atoms 3. Balance Oxygen with water 4. Balance Hydrogen with H+ 5. Balance charge with e- 6. Normalize Equation