1. University of California,
Chapter 1
Remembering General Chemistry: Electronic Structure and Bonding
Paula Yurkanis Bruice
University of California,
Santa Barbara

2. Contents of Chapter 1 Bonding, Lewis Structures
Atomic & Molecular Orbitals
Hybrid Orbitals
Single Bonds
Multiple Bonds
Chapter 1

3. Ionic Bonds
Chapter 1

4. Covalent Bonds
covalent bond
Chapter 1

5. Polar Covalent Bonds
Chapter 1

6. Bond Polarity Depends on Electronegativity Differences

7. Polar Covalent Bonds
There is a continuum of bonding types
Chapter 1

8. Lewis Structures
The chemical symbols we have been using in which valence electrons are shown as dots are called Lewis structures
Chapter 1

9. Drawing Lewis Structures
Write the symbols for the elements in the correct structural order
Consider nitric acid, HNO3
Chapter 1

10. Sticks and Eyeballs Bonds + Lone Pairs = 4 (Octet Rule)
Exceptions: H has 1 bond, B has 3 bonds
Bonds: Count spaces from noble gas
Convert bond to LP is (-), LP to bond is (+)
Exceptions: C(+), B(-)
Chapter 1

11. Formal Charges
Subtract the number of assigned electrons from the number of valence electrons (core charge) for an uncombined atom of the same element
6 - 6 = 0
1 - 1 = 0
6 - 7 = -1
6 - 6 = 0
5 - 4 = +1
Chapter 1

12. Condensed Structural Formulas
Kekulé formulas also are called structural formulas
Often, structural formulas are condensed
becomes
Chapter 1

13. 1s and 2s Orbitals
Chapter 1

14. 2p Orbitals
Chapter 1

15. Molecular Orbital From p Electrons
Molecular orbitals also can be formed from p orbitals
Chapter 1

16. Hybrid Orbitals
Methane, CH4, has four equivalent carbon-hydrogen bonds
Chapter 1

17. Hybridization
Theory: Mix the 2s orbital with the three 2p orbitals to form four equivalent hybrid orbitals
Chapter 1

18. Hybridization - Tetrahedral Carbon
The sp3 hybrid orbital on carbon also can bond with another sp3 hybrid orbital from a neighboring carbon to form a carbon-carbon single bond
Chapter 1

19. sp2 Hybridization in Ethene
The carbon-carbon bond formed from the overlap of an sp2 orbital on one carbon with an sp2 orbital on a neighboring carbon atom results in an orbital which is cylindrically symmetric about the carbon-carbon axis
Chapter 1

20. sp2 Hybridization in Ethene
A second bond is formed between the two carbon atoms via the side-by-side overlap of the remaining (un-hybridized) p orbitals
Electron density accumulates above and below the carbon-carbon axis
Chapter 1

21. sp Hybridization in Ethyne
The overlap of the sp hybrid orbitals forms a  bond
Chapter 1

22. sp Hybridization in Ethyne
The remaining p orbitals overlap side-by-side, forming  bonds with electron density above and below the carbon-carbon axis as well as in front and in back
Chapter 1

23. Summary of Orbital Hybridization
Count the number of objects attached to an atom. Each LP is an object, each neighboring atom is an object.
Each object needs one orbital to build hybrids
Start with an s orbital, then use up to 3 p orbitals as needed
Only LP’s remain in hybrids when bonds form
Chapter 1

24. Summary of Orbital Hybridization
Chapter 1