題組內容

(5) (10 pts) Plcase describe in dctail how the atmospheric composition changed, starting from the Earth formed to now.
6 Table A lists the major redox processes occurring in the sediments and their redox potential (611c75be66278.jpg, in volt) at 25 C. I atmi, unit activity, and pH = 7. In the ecosystemn, animals and microbes usually perform respiration through the oxidation of carbohydrates to get energy and release CO2. Dependent on the environment, diflerent proces sses will be performed.

(d)Nitrification is the biological oxidation of ammonium to nitrite, followed by the oxidation of nitrite to nitrate under aerobic conditions. 
 (i) (4 pts) Please write the nitrification net reaction with a reactant of amnonium and the final product as nitrate.
 (ii) (8 pts) If global net primary productivity on land is 611c76ce04190.jpg g C/yr, and the average C/N ratio of plant biomass is 100, what is the upper limit (i.e., maximum estimate) of oxygen used every year in microbial nitrification?