Final Answer:
The type of bond between two incomplete outer shells is an ionic bond.
Step-by-step explanation:
Ionic bonds form when atoms transfer electrons, resulting in the formation of ions with opposite charges. Atoms with incomplete outer shells either lose electrons to achieve a stable, noble gas configuration or gain electrons to fill their outer shell. The electrostatic attraction between these oppositely charged ions creates the ionic bond.
In the process of ionic bonding, consider the example of sodium (Na) and chlorine (Cl). Sodium has one electron in its outer shell, which it donates to chlorine, having seven electrons in its outer shell. Sodium becomes Na⁺, and chlorine becomes Cl⁻. The resulting electrostatic attraction between Na⁺ and Cl⁻ forms an ionic bond in sodium chloride (NaCl). This bond is characterized by the complete transfer of electrons from one atom to another, leading to the stability of both atoms.
In summary, an ionic bond arises between atoms with incomplete outer shells as they transfer electrons to achieve a more stable electronic configuration. The resulting electrostatic interaction between ions of opposite charges creates a strong bond known as an ionic bond, exemplified by compounds like NaCl.