The nucleus of an atom can be modeled as several protons and neutrons closely packed together. Each particle has a mass of 1.67 10-27 kg and radius on the order of 10-15 m. (a) Use this model and the data provided to estimate the density of the nucleus of an atom.

Cin carbonh in hydrogeno in oxygen

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.