Ionic Compounds
Ionic compounds are held together by electrostatic attraction between oppositely charged ions, forming crystalline lattices.
Ionic Compounds
Ionic compounds form when atoms transfer electrons to achieve full valence shells. The resulting cations (positive) and anions (negative) are held together by electrostatic forces.
Formation
A classic example is sodium chloride:
- Na (1 valence e⁻) loses e⁻ → Na⁺
- Cl (7 valence e⁻) gains e⁻ → Cl⁻
- Na⁺ and Cl⁻ attract → NaCl lattice
Properties
| Property | Ionic Compounds | Covalent Compounds |
|---|---|---|
| Melting point | High | Low |
| Electrical conductivity | When molten/dissolved | Poor |
| Solubility in water | Often high | Varies |
| Structure | Crystalline lattice | Discrete molecules |
Electronegativity Difference
The ΔEN between Na (0.93) and Cl (3.16) is 2.23, well above the 1.7 threshold for ionic bonding. In general, metals on the left of the periodic table combine with non‑metals on the right to form ionic compounds.
Related molecules: Sodium Chloride
Learn more: Chemical Bonding