The poly atomic ion formula for ammonium would be NH4+
A fertilizer or fertiliser is any material of natural or synthetic origin that is applied to soil or to plant tissues to supply plant nutrients. Fertilizers may be distinct from liming materials or other non-nutrient soil amendments. Many sources of fertilizer exist, both natural and industrially produced
The degree of polarity of diatomic molecule is related to the difference of electronegativity of the two atoms. If the difference is very large, i.e. one atom is highly electronegative and the other atom is highly electropostive then, the covalent bond is formed. But if the difference between the electronegativities is very less, then its likely that ionic bond is formed.
