ACS Chemistry Practice Exam 2025 – The All-in-One Guide to Exam Success!

The presence of an electronegativity difference of 1.7 or greater typically signifies the formation of an ionic bond. This is because a significant electronegativity difference between two atoms leads to the complete transfer of electrons from one atom to another, resulting in the formation of ions.

In ionic bonding, one atom, often a metal, donates one or more of its electrons to another atom, typically a non-metal, which accepts the electrons. The metal becomes a positively charged ion (cation), while the non-metal becomes a negatively charged ion (anion). The strong electrostatic attraction between these oppositely charged ions forms the ionic bond.

Covalent bonds, on the other hand, result from the sharing of electron pairs between atoms with similar electronegativities, usually with a difference of less than 1.7. Polar bonds, while also involving unequal sharing of electrons due to a smaller electronegativity difference, do not indicate complete transfer, which is characteristic of ionic bonds. Metallic bonds involve a different type of electron interaction where there is a 'sea of electrons' surrounding positively charged metal ions, not applicable in the context of the given electronegativity difference.