Could somebody please help me? Type the correct answer in the box. Spell all words correctly

Which step in the nitrogen cycle is responsible for returning fix nitrogen back into the atmosphere?

(Blank) is a process in which certain types of bacteria present in the soil convert nitrates into nitrogen gas

Thank you! :)

satellites are frequently used to make observations of the orbit on earth

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.