Which of the following bonds is the strongest due to complete electron transfer?

The strongest bond due to complete electron transfer is the ionic bond. This type of bond forms when one atom donates one or more of its electrons to another atom, resulting in the formation of positively and negatively charged ions. The attraction between these oppositely charged ions generates a strong electrostatic force, which characterizes ionic bonds.

In contrast, hydrogen bonds are a type of dipole-dipole interaction and are much weaker than ionic bonds. They occur due to the attraction between a hydrogen atom bonded to a more electronegative atom and another electronegative atom. Covalent bonds involve the sharing of electron pairs between atoms, which can also create strong connections, but they do not involve the complete transfer of electrons as ionic bonds do. Dative bonds, or coordinate covalent bonds, involve a shared pair of electrons where one atom provides both electrons, but this is still not synonymous with the complete transfer characteristic of ionic bonding.

Overall, the distinctive feature of ionic bonding—the complete transfer of electrons from one atom to another—results in particularly strong bonds due to the resultant electrostatic attraction between the charged ions.