Ionic Bonding Concepts

Ionic Bonding

• Ionic bonding is the electrostatic attraction between oppositely charged ions.
• It occurs when a metal atom loses one or more electrons to become a positively charged cation, and a nonmetal atom gains those electrons to become a negatively charged anion.
• The electrostatic attraction between the oppositely charged ions forms a crystal lattice structure.
• This structure is characterized by high melting and boiling points.
• Ionic compounds are typically formed between metals (low ionization energy) and nonmetals (high electronegativity).
• The transfer of electrons results in the formation of ions with complete outer electron shells, attaining a stable electron configuration.

Formation of Ionic Bonds

• Electron transfer from a metal to a nonmetal creates ions.
• The metal loses electrons, becoming a positive ion (cation).
• The nonmetal gains electrons, becoming a negative ion (anion).
• The opposite charges attract each other strongly creating an ionic bond.
• The attraction holds the ions together in a 3D crystal lattice structure.
• The strength of the ionic bond depends on the charges on the ions and their size (smaller ions lead to stronger bonds).
• The process involves energy changes (ionization energy and electron affinity)

Properties of Ionic Compounds

• High melting and boiling points: Strong electrostatic forces between ions require a significant amount of energy to overcome.
• Brittle: Applying pressure can cause ions with the same charge to line up, leading to repulsion and the crystal structure breaking.
• Conductivity: When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move.
• Solubility: Many ionic compounds are soluble in polar solvents like water due to the attraction between the ions and the polar molecules of the solvent.
• Crystalline structure: The ions arrange themselves in a regular, repeating pattern in a crystal lattice.
• Hard: The strong electrostatic forces between ions result in hard, rigid solids.
• Non-conductivity in solid state: In a solid state, the ions are fixed in place within the crystal lattice, and therefore cannot conduct electricity.
• Solubility depends on the relative strength of attractions between ions and solvent molecules. Solvents with high polarity tend to dissolve ionic compounds effectively.
• Formation of strong electrolytes: Ionic compounds dissolve in water to form ions that dissociate completely.