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Bonding, metallic bonding, metallic materials

Short answer

Bonding is the attractive force between atoms that forms stable substances. Metallic bonding occurs when metal atoms release valence electrons into a common pool, with positive ions held by the free electron cloud (e.g. iron, copper). Metallic materials are strong, ductile, good conductors, lustrous, dense, tough, recyclable and can be alloyed, welded and heat‑treated.

Define bonding. Explain metallic bonding with example. Write the important characteristics of metallic materials.

Bonding

Bonding is the attraction between atoms, ions or molecules that holds them together to form a stable substance. It arises from the tendency of atoms to reach a stable electron configuration. The main types are ionic, covalent, metallic and secondary (van der Waals, hydrogen) bonds.

Metallic bonding with example

In metallic bonding, each metal atom gives up its valence electrons to a common pool. The resulting positive ions form a regular lattice, held together by the attraction of the freely moving electron cloud. The bond is non-directional and not tied to particular atoms.

Example: in iron or copper, the valence electrons are shared by the whole crystal. When a load is applied, layers of ions slip over each other and the electron cloud keeps holding them, so the metal deforms without breaking.

  (+) (+) (+) (+)
   .  .  .  .  .   electron sea
  (+) (+) (+) (+)

Important characteristics of metallic materials

  1. High strength and stiffness.
  2. Ductile and malleable, so they can be drawn and rolled.
  3. Good conductors of heat and electricity.
  4. Metallic lustre and opacity.
  5. High density and fairly high melting point.
  6. Tough, and can withstand impact and fatigue (steel).
  7. Can be alloyed, welded, cast and heat treated to modify properties.
  8. Prone to corrosion in moist air, so they need protection.
  9. Recyclable.

✓ Answer checked by Claude Opus 5.5 (high effort)

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