Ammonia is a colorless, alkaline gas which is formed when organic substances are decomposed in the body during different reactions.
You have asked for the structural formula which shows the arrangement of the molecules in a compound, but since I cannot draw it here so I will explain in words and hope to make it clear.
Ammonia consists of molecules of nitrogen and hydrogen in the ratio 1:3. Therefore its chemical formula is NH[3]. Its structural arrangement shows one atom of Nitrogen (N) bonded with three atoms of Hydrogen (H).
