1. Chemical Compounds and Bonding Ionic compounds ionic bond steal (transfer) electrons Molecules covalent bond share electrons

2. Properties of Ionic Compounds Metal/nonmetal Ionic bonds Transfer electrons Strong +/- attraction High boiling/melting point Solids Brittle Molten Conduct heat/electricity

3. Molecules 2 non-metals Covalent bonding – sharing electrons Weak attractions Low boiling/melting points Gases,solids, liquids, Do not conduct electricity

4. Electron Dot Formulas for elements Show valence electrons only ***Remember families

5. Octet Rule An atom will gain or lose electron to have an octet (or filled) valence energy level

6. Ionic bonds Electron dot write cation, anion

7. Covalent bonding Share electrons to form an octet ****except H – it shares to get 2 Single double triple coordinate bonds Electron- dot formula Structural formula

8. Structural Formula Shows bonding without electrons 1 pair of electrons equals 1 single bond

9. Make a table Chemical Electron dot Structural Bond Molecule Formula FormulaFormula Type Type

10. Electronegativity Desire to steal another atom’s electron EN differenceType of bond 0-.4nonpolar covalent.5-1.9polar covalent 2.0 +ionic bond

11. Determine bond type Use Electronegativity table p440 H=2.1 Cl=3.0Br=2.8 F=4.0O=3.5I=2.1 C=2.5 H=2.1 Na=.9F=4.0 S=3.0N=3.0 P=2.5K=0.8 Si-2.0Mg=1.0

12. Molecule Type Look at the molecule polar – 2 different “ends” non-polar – same “ends”

13. Cl 2 S 2 P 2 H 2 O CF 4 *****remember C CF 3 H

14. C 2 H 6 H 2 O 2 HCN C 2 H 4 CH 2 O SiO 3 -2 PO 4 -3

15. Molecular shapes see page 457 Linear Trigonal planar Tetrahedral Trigonal pyrimidal Bent

17. Exceptions to Octet rule BF 3 PCl 5

18. Resonance Having 2 or more correct electron dot structures that are different CO 3 -2

19. VSEPR Theory valence shell electron pair repulsion theory Bond angles are different ( usually less) due to electrons repelling other electrons Water should be 109.5 o but it is 104.5 o