1. Metallic Bonding

2. Metallic Bonds are… How metal atoms are held together in the solid.
Metals hold on to their valence electrons very weakly.
Think of them as positive ions (cations) floating in a sea of electrons

3. The Metallic-Bond Model
The vacant orbitals in the atoms’ outer energy levels overlap.
Overlapping orbitals allow the outer electrons of the atoms to roam freely throughout the metal.
Electrons are delocalized (they do not belong to any one atom but move freely)
Mobile electrons form a sea around the metal atoms, which are packed together in a crystal lattice.

4. Sea of Electrons + Electrons are free to move through the solid.
Metals conduct electricity. +

5. Metals are Malleable Hammered into shape (bend).
Also ductile - drawn into wires.
Both malleability and ductility explained in terms of the mobility of the valence electrons

6. Malleable +
Force

7. Malleable + + + + Force + + + + + + + +
Mobile electrons allow atoms to slide by, sort of like ball bearings in oil. + + + +
Force + + + + + + + +

8. Ionic solids are brittle
Force + -

9. Ionic solids are brittle
Strong Repulsion breaks a crystal apart, due to similar ions being next to each other. + -
Force + - + - + -

10. Crystalline structure of metal
If made of one kind of atom, metals are among the simplest crystals; very compact & orderly
Sodium