Answer: ammonia
Notes: Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, Ammonium (NH4+), nitrite (NO2–), nitrate (NO3–), nitrous oxide (N2O), Nitric oxide (NO) or inorganic nitrogen gas (N2). For organisms to use atmospheric nitrogen (N2), it must be “fixed” or converted into ammonia (NH3).The processes of the nitrogen cycle transform nitrogen from one form to another. It involves nitrification, the conversion of ammonia (NH3) to nitrate (NO3–). Ammonia does not contain oxygen.
