In a disaster at sea, life vests (also called personal floatation devices, or PFDs) can save lives. If you were to design a PFD, what material would you use? Why? Be sure to
use the word "density" in your explanation. You may use internet resources to answer
this question. (2 sentences)

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.