When the electron moves back to lower energy levels in an electron transport chain, energy is a) stored or b) released c)converted to matter d)used to make O2

I'm not sure how to answer this cause isn't it stored as potential energy of H20 and just before the electron moves back the energy is released. So when it moves back would it be considered stored?

3 answers

No, if an electron goes to a lower energy level, energy is released.
C
) Converted to matter is not the correct answer. When an electron moves back to lower energy levels in an electron transport chain, the energy is released. Therefore, the correct answer is b) released.