Metallic Bonding and Properties of Metals

Overview

• Metallic Bonding: Occurs between metal atoms.
• Characteristic Properties of Metals: Result from metallic bonding.
• Alloys: Differ from pure metals and offer enhanced properties.

Types of Bonding Recap

• Ionic Bonding: Occurs between metals and non-metals.
• Covalent Bonding: Occurs between non-metals.

Metallic Bonding

• Involves metals bonding with other metals.
• Structure of Solid Metal:
  • Consists of a giant structure of atoms in a regular pattern.
  • Atoms give up outer shell electrons, becoming positive ions.
  • Electrons are delocalized and free to move throughout the metal.

Characteristics of Metallic Bonding

• Electrostatic Attraction: Strong forces between positive ions and delocalized electrons.
  • Holds the metal atoms together in a regular structure.

Properties of Metals

• Strength: Due to metallic bonding.
• High Melting and Boiling Points: Metals are solid at room temperature.
• Conductivity:
  • Good conductors of electricity and heat.
  • Delocalized electrons can carry electrical current and thermal energy.
• Malleability:
  • Metals can be bent or hammered into shapes (e.g., thin sheets).
  • Regular structure allows layers to slide over one another.

Alloys

• Purpose: To create harder metals that do not bend easily.
• Composition: Two or more different elements.
  • Mixture of different metals or metal and non-metal.
  • Elements with different-sized atoms disrupt the regular structure.

Example: Steel

• Composition: Mostly iron with 1-2% carbon.
• Additional Elements: Chromium, manganese, or vanadium for specific properties.
• Application: Used in cars and planes for enhanced strength.

Conclusion

• Metallic bonding explains the strength, conductivity, and malleability of metals.
• Alloys provide tailored properties for specific applications.