Covalent compounds are formed between nonmetals.
Examples of nonmetals
H , O , N , C , S , P , F , Cl , Br , I.
Examples of covalent compounds: - CH2O, H2O etc.,
Ionic compound is formed between a metal and nonmetal.
Examples of ionic compound: - CuSO4, NaCl.
NH4^+ = ammonium ion it is a polyatomic ion it form ionic salt which are ionic in nature
Example:- NH4Cl, (NH4)3PO4 etc.,
Ionic compounds are formed by transfer of electron between a metal atom and nonmetal atom.
Covalent compounds are formed by sharing of electrons between two nonmetals atoms.
Number of electron transferred can be determined by electronic configuration or by knowing the oxidation states.