1. CHM 108 SUROVIEC SPRING 2014 Chapter 9

2. I. Types of Bonds Chemical bonds form because they lower the energy between charged particles When 2 atoms approach each other the nucleus of 1 is attached to the electrons of the other The electrons of one atom are also repelled by the electrons of the other

3. II. Lewis Structures The electrons in the valence shell are the electrons that participate in bonding Many Nobel gas atoms are extremely unreactive because they have their outer shell filled.

4. III. Ionic Bonds The transfer of an electron from 1 atom to another Example: NaF Example: MgCl 2

5. IV. Covalent Bonding A. Single covalent bond  Bonding pairs are shared between atoms B. Lone pairs  Valence electrons usually occur in pairs

6. IV. Covalent Bonding C. Multiple bonds  Atoms can also share more than one electron pair

7. V. Resonance Forms In some cases a Lewis structure does not adequately describe the properties of the ion/molecule that it represents

8. A. Formal Charge Often it is possible to write 2 different Lewis structures for a molecule where the atoms are rearranged

9. Example CH 2 O

10. B. Exceptions to the Octet Incomplete Octet Expanded Octet