1. The Metallic bond

2. A metallic bond is formed when a group of metallic atoms “communally” share their valence electrons with the group. When metal atoms “lose” their valence electrons, they become cations ( positive ions ). The Metallic bond Cu Cu Cu Cu Cu 1+ Cu 1+ Ex. (1)

3. Cu 1+ Cu 1+ The metallic cations are held together by a mobile sea of electrons ( usually valence electrons ) that were donated by each individual member of the group. In this way, each metallic cation achieves a full valence and stability. The Metallic bond Ex. (1) copper metal

4. Ex. (2) Ex. (3) The Metallic bond Zn : Zn : Cu Zn : Zn : Cu Zn : Cu Cu Zn : Cu 1+ Zn 2+ Zn 2+ Cu 1+ Cu 1+ Zn 2+ Brass Metal Zn 2+ Zn 2+ Zinc Metal

5. Al : Ex. (4) Ex. (5) Write “PCB” under the formulas that have polar covalent bonding and “NPCB” under the formulas that have nonpolar covalent bonding. O 3 CH 4 I 2 NH 3 The Metallic bond Al 3+ Aluminum Metal NPCBPCBNPCBPCB

6. Ex. (6) Under formulas write “IB” for ionic bonding, “MB” for metallic bonding, “PCB” for polar covalent bonding, “NPCB” for nonpolar covalent bonding, and “NB” if no bonding is present. FeCl 3 H 2 S Au C Na 2 O Fe PH 3 Rn SiO 2 MgS He P 4 The Metallic bond IBPCBMBNPCB IBMBPCBNB PCBIBNBNPCB

7. Br Ex. (7) Draw a Lewis dot structure for: (a) calcium oxide and (b) hydrogen bromide. (a) (b) Ca [ ] O The Metallic bond Ca O [ ] 2+ 2- H Br H scratch workfinal answer Br H _