Ionic and covalent compounds represent two fundamental types of chemical bonding, characterized by distinct mechanisms for the interaction of atoms.

Ionic compounds arise when a metal reacts with a non-metal. These compounds consist of positive and negative ions, which are held together by strong electrostatic forces of attraction, a phenomenon known as ionic bonding. In this process, metal atoms lose electrons, transforming into positively charged ions, while non-metal atoms gain these electrons, resulting in negatively charged ions. The overall charge of the ionic compound remains neutral, as the total positive charge from the metal ions balances the total negative charge from the non-metal ions. Ionic compounds typically form crystalline structures and exhibit high melting and boiling points due to the robust forces of attraction between the ions.

Conversely, covalent compounds form when two non-metals react with one another. In this case, instead of transferring electrons as in ionic bonding, the atoms share electrons, a process referred to as covalent bonding. Each atom contributes at least one electron to the shared pair, commonly known as a bonding pair of electrons. The shared electrons are attracted to the nuclei of both atoms, which stabilizes the covalent bond. Covalent compounds can exist as simple molecules or as extensive covalent networks. Simple molecular substances tend to have low melting and boiling points and do not conduct electricity, whereas giant covalent structures require significant energy to break the numerous strong covalent bonds, resulting in high melting and boiling points.

In summary, the primary distinction between ionic and covalent compounds lies in the nature of the atomic bonding. Ionic compounds involve the transfer of electrons and the formation of ions, whereas covalent compounds involve the sharing of electrons between atoms.