The molecules in ammonia are bonded together by covalent bond; this is the type of bond in which electrons are shared among atoms in the compound. Ammonia is a polar molecule and is made up of one nitrogen atom and three hydrogen atoms. The hydrogen atom in ammonia is bonded to the three hydrogen atoms via sharing of three electron pairs, one with each atom of hydrogen. For each of the three covalent bond formed, one electron is supplied by nitrogen and one by hydrogen atom.