Which Elements Are Electron Donors?

Which Elements Are Electron Donors? Some prokaryotes can use inorganic matter as an energy source. Such organisms are called lithotrophs (“rock-eaters”). Inorganic electron donors include hydrogen, carbon monoxide, ammonia, nitrite, sulfur, sulfide, and ferrous iron. Which molecule is only an electron donor? Now there is no vacant p-orbital present in nitrogen so, ammonia molecule is