1. Metallic Bonding

2. Review
all atoms in a metallic bond have low electronegativity.

3. Shape of metallic bonding
close-packed lattice – atoms packed together like oranges in a box.

4. valence e- shared by all the atoms (delocalized)
no valence e- belongs to any particular atom
all valence e- move throughout the sample of metal

6. metal atoms are cations
attracted to the moving e-
provides a force that holds the metal sample together

7. Electron Sea Model
a lattice of positive ions filled by a “sea” of electrons

8. Properties of metals
layers of ions can slide past one another without breaking the cation-e- bond
unlike an ionic compound!

9. metals are:
malleable: can be hammered into different shapes

10. ductile: can be pulled into wire

11. e- can move anywhere in the lattice
conduct (move) electricity and heat

12. Most metals are hard at room temp.
high melting and boiling points
Exception: Mercury, liquid at r.t.p.

13. Electrical conductivity
depends on presence of electrically charged particles that can move throughout the compound