1. Chemical Bonding Ionic Compounds

2. Ionic Compound: 1. ionic compounds form crystals 2. high melting and boiling points 3. hard and brittle 4. conduct electricity when dissolved in water or melted Properties Composed of a metal (cation) and nonmetal (anion) Ionic bond – oppositely charged ions attract Electrically neutral (+) = (-)

3. Steps to Ionic Bonding Copy the problem Draw the Lewis Structure for ea. element used in bonding CATION = RED ANION = BLUE/GREENISH Show donated e - with an arrow Show New ions charges Put a BOX around the Formula

4. Ionic Bonding Na Cl 1. Sodium and Chlorine ● ●● ● ● ● ● ● donates e - Na + ● Cl ● ● ● ● ● ● ● 2. Potassium and Oxygen K O ● ● ● ● ● ● donates e - K+K+ ● O ● ● ● ● ● ● ● ● + + K ● K+K+ -2 +1-2 - K2OK2O NaCl +1 Does O have 8?

5. Al 3. Aluminum and Bromine Mg N ● ● ● ● ● Mg +2 ● N ● ● ● ● ● ● ● ● + ● -3 ●● ● ● ● ● ● ● Al + 3 ● Br ● ● ● ● ● ● ● + ● ● ●● ● ● ● ● ● ●● ● ● ● ● ● +3 ● Br ● ● ● ● ● ● ● ● ● ● ● ● ● ● ● - - - +2 -3 Mg 4. Magnesium and Nitrogen Mg ● ● ● ● N ● ● ● ● ● Mg +2 ● N ● ● ● ● ● ● ● -3 AlBr 3 Mg 3 N 2 Does Al have more electrons? Does N have 8 yet? What about Mg’s other e-? Does N have 8 yet?

6. Characteristic Covalent compound Molecular compound Ionic compound Representative unit Molecule (atoms sharing electrons) Formula unit (balance of oppositely charged ions) Type of elementsNonmetallic Metallic combined with nonmetallic Melting & Boiling point LowHigh Important differences between covalent and ionic compounds

7. Bonding in Metals Metallic bonds – the attraction between positive ions and surrounding mobile electrons Sea of Electrons Metal cations Good conductors of electrical current, ductile (wires), malleable (forced into shapes)