Hydrogen and oxygen release enormous amounts of energy when they react. Yet, hydrogen and oxygen can be mixed together in a balloon and nothing will happen. Why?

• A. There must be contaminating elements in the balloon that prohibit the reaction from occurring
• B. All of these
• C. The energy of activation to form the transition-state complex is too high to allow the reaction to occur without assistance
• D. Competitive inhibitors are blocking the reaction from occurring in the active site

Answer: (D)