What are coordinate covalent bonds?

A coordinate covalent bond, also known as a dative bond, is a type of covalent bond where both electrons come from the same atom. This occurs when one atom with a lone pair donates it to an atom or ion that lacks electrons. A classic example is the bond in ammonium ion (NH₄⁺), where nitrogen donates a lone pair to a proton (H⁺). Though formed differently, coordinate bonds behave like regular covalent bonds once formed. They are important in complex ions, transition metal chemistry, and acid-base reactions.