WJEC Chemistry Practice Exam

An ionic bond is characterized by the transfer of electrons from one atom to another. This process typically occurs between atoms with significantly different electronegativities. When one atom (often a metal) loses one or more electrons, it becomes positively charged, while the other atom (typically a nonmetal) gains those electrons, becoming negatively charged. The resulting electrostatic attraction between the oppositely charged ions forms the ionic bond.

In contrast, a covalent bond involves the sharing of electrons between atoms, leading to the formation of molecules. Metallic bonds are formed by a sea of delocalized electrons that move freely around metal cations, allowing for conductivity and malleability. Hydrogen bonds are a type of weak interaction that occurs between molecules, particularly involving hydrogen and electronegative atoms like oxygen or nitrogen, rather than a straightforward transfer of electrons. Thus, the distinct process of electron transfer is what defines the nature of ionic bonds.