Metallic Bonding and Properties of Metals

Metallic Bonding Basics

• Involves only metal atoms.
• Pure metals have a regular lattice structure of tightly packed atoms.
• Metals have low electronegativity, causing them to lose outer shell (valence) electrons easily.
• Lost electrons become 'delocalised,' forming a 'sea' of free-moving electrons around positively charged metal cations.
• Metallic bonds are strong electrostatic attractions between these positive cations and the surrounding delocalised electrons.

Properties of Metals

• High Melting Points: Due to strong electrostatic attraction requiring significant energy to overcome. Melting point increases with the number of delocalised electrons per atom, strengthening the bond.
• Good Thermal Conductors: Delocalised electrons gain kinetic energy when heated, move faster, and transfer this energy throughout the metal via collisions.
• Good Electrical Conductors: Free-moving delocalised electrons (charged particles) are attracted to a positive terminal when an electric current is applied, creating a flow of charge.
• Malleable: Layers of metal ions can slide past one another without shattering because the delocalised electron sea maintains the electrostatic attraction, preventing strong repulsive forces.
• Ductile: Similar to malleability, the delocalised electrons allow layers of ions to slide while maintaining structural integrity, enabling metals to be drawn into wires.
• Lustrous (Shiny): Delocalised electrons reflect light.