- 2065 Shrawan (old course) · 4 marks
Metallic bond versus covalent bond
Short answer
A metallic bond forms by attraction between positive metal ions and a sea of delocalized electrons, is non‑directional, and results in good conductivity and ductility. A covalent bond arises from shared localized electron pairs between atoms, is directional, and yields hard, brittle materials with poor conductivity.
Differentiate between metallic and covalent bond.
| Basis | Metallic bond | Covalent bond |
|---|---|---|
| Formation | Attraction between positive metal ions and a sea of free electrons | Sharing of electron pairs between two atoms |
| Electrons | Delocalised, free to move | Localised between the bonded atoms |
| Direction | Non-directional | Directional (fixed bond angles) |
| Conductivity | Good electrical and thermal conductor | Generally poor conductor |
| Mechanical nature | Ductile and malleable | Hard and brittle |
| Melting point | Moderate to high | Very high (diamond) or low (molecular solids) |
| Lustre | Metallic lustre | Usually none |
| Examples | Iron, copper, aluminium | Diamond, silica, polymers |
✓ Answer checked by Claude Opus 5.5 (high effort)
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