What is an ionic bond?

An ionic bond is defined as a bond between two ions that have opposite charges. This type of bonding occurs when one atom donates an electron to another atom, resulting in the formation of positively charged ions (cations) and negatively charged ions (anions). The electrostatic attraction between these oppositely charged ions leads to the bond formation.

In contrast, the other options describe different types of interactions. The sharing of electrons pertains to covalent bonds, where atoms share pairs of electrons. The sharing of protons is not a common way to describe bond formation in chemistry, and protons do not typically form bonds in the way electrons do. Lastly, the description of a weak attraction between neutral molecules relates to van der Waals forces or hydrogen bonding, which are much weaker than ionic bonds. Thus, the nature of ionic bonds is fundamentally about ion interactions resulting from charge differences, making the first answer the most accurate description.