In which type of chemical bond does one atom completely donate an electron to another atom?

An ionic bond is formed when one atom completely donates an electron to another atom. This process typically occurs between atoms with significantly different electronegativities, such as metals and non-metals. When the donor atom, usually a metal, loses one or more electrons, it becomes a positively charged ion (cation). Conversely, the recipient atom, typically a non-metal, gains electrons to become a negatively charged ion (anion). The electrostatic attraction between these oppositely charged ions leads to the formation of the ionic bond.

In contrast, a covalent bond involves the sharing of electrons between two atoms rather than the complete transfer of an electron. This type of bond usually occurs between non-metals that have similar electronegativities. Hydrogen bonds, on the other hand, are weaker interactions that occur when a hydrogen atom covalently bonded to a highly electronegative atom is also attracted to another electronegative atom. Metallic bonds consist of a sea of delocalized electrons shared among a lattice of metal cations, which is a different bonding mechanism altogether. Understanding these distinctions is crucial in grasping the nature of different types of chemical bonds in various compounds.