1. Suppose you had come along before Mendeleev and were tasked with organizing the elements into a pattern others could understand. Describe your
arrangement and how you would determine where elements would be placed.
Can you think of any problems your design might create?

The answer is water molecules are split.cellular respiration and photosynthesis are complement  reactions to each other. these are reverse reactions. in cellular respiration glucose and oxygen yield water and carbon dioxide. so, when respiration begins,  glucose molecules are split. in the opposite reaction - in photosynthesis, carbon dioxide and water yield glucose and oxygen. thus,  when respiration begins, water molecules are split.