Concept:A coordinate (dative) covalent bond is formed because one atom donates both electrons of the shared pair.
Explanation:In
H2O, oxygen carries two lone pairs of electrons.
The hydrogen ion,
H+, has an empty 1s orbital.
When
H+ approaches water, it accepts a lone pair from oxygen.
Both electrons in the new bond come from the oxygen atom, so the shared pair is donated by only one atom.
This type of bond is called a dative covalent bond.
The ion produced is the hydroxonium ion,
H3O+.
Therefore, the bond is neither an ordinary covalent bond, an electrovalent bond, nor an ionic bond.
Answer:A. Dative