According to passage information, is the energy released by the transport of an electron pair delivered by nadh through the electron transport chain sufficient to produce three atp molecules from three adp and three inorganic phosphate molecules if the efficiency of the conversion of the energy released via the transport of an electron delivered by nadh into useful work in the body is found to be approximately 50%?

yes with the majority of the calories of energy released by the electron transfer and not used in the phosphorylation lost mainly as heat

the passage states that to convert ADP to ATP it's about 7.3 kcal/mol. we should multiply this by 3 moles (to represent 3 molecules of ATP) and to get an approx. 22 kcal. The passage also states that 52.5 kcal/mol released for the transfer of two electrons from NADH to oxygen after taking into account 50% efficiency approximately 26 kcal/mol is a useful energy. So there is sufficient energy and the remaining 4 kcal/mol will be dissipated as a heat.

C14 dating since carbon is present in both living and no living objects .