Covalent compounds are formed by the sharing of electron pairs between atoms, typically non-metals. Unlike ionic compounds, they exist as discrete molecules held by weak intermolecular forces.
- Physical State: Usually exist as gases, liquids, or soft solids at room temperature.
- Low Melting/Boiling Points: Weak intermolecular forces require little energy to overcome compared to strong ionic crystal lattices.
- Electrical Conductivity: Generally non-conductors (insulators) because they lack free ions or delocalized electrons.
- Solubility: Generally soluble in non-polar organic solvents (like benzene) and insoluble in water (with exceptions like polar covalent molecules).
- Directional Bonding: Covalent bonds are directional, which gives rise to specific molecular geometries (e.g., linear, tetrahedral).
Structure & Bonding
In covalent compounds, atoms share electrons to achieve a stable octet configuration. This creates strong covalent bonds within the molecule, but the attraction between separate molecules remains weak.
Summary Table
| Property | Covalent Characteristic |
|---|---|
| Bonding Type | Electron sharing |
| Intermolecular Force | Weak (Van der Waals) |
| Conductivity | Poor (Insulators) |
Practice Questions
View Answer & Explanation
The strong covalent bond exists only within the molecule. Melting the substance only requires separating the molecules from each other, which only involves overcoming weak intermolecular forces.
View Answer & Explanation
Diamond is a covalent network solid where every carbon atom is covalently bonded to four others in a 3D structure, resulting in an exceptionally high melting point and hardness, unlike typical molecular covalent compounds.