Chemical bonding and Molecular Structure

1. 3 – Lecture Chemical bonding and Molecular Structure

Azamat Amzebek

2. Topics Covered

Ionic Bonds and Compounds
Covalent Bonds
Lewis Structures
Types of Covalent Bonding
Geometry and Polarity of Covalent Molecules
Orbital Hybridization
Sigma and Pi Bonds

3. Chemical bond

The atoms in molecules held together by strong
attractive forces called chemical bonds
Formed by interaction of valence electrons of
the combining atoms
In the formation chemical bonds atoms bond
according to the octet rule

4. Ionic bond

Two atoms with large difference in
electronegativity reactivity, there is complete
electron transfer
High electronegativity == anion
Low electronegativity == cation

5. Ionic bond

These two ions are held together by
electrostatic forces
This force of attraction between the charged
ions is called an ionic bond

6. Nomenclature

1.
2.
3.

7. Nomenclature

4.
5.

8. Nomenclature

6.

9. Ionic bond

High melting and boiling point – strong
electrostatic force
Conduct electricity in liquid and aqueous states

10. Covalent Bonds

Forms when two elements have similar
electronegativities
They achieve a noble gas electron
configuration by sharing electrons in what is
known as a covalent bond
Sometimes need more than one electron to
form octet

11. Covalent bond

Bonds length is the average distance between
the two nuclei of the atoms involved
Bond energy is the energy required to separate
two bonded atoms

12. Bonds

Primary bonding – covalent and ionic
Secondary – hydrogen and Van der Vaals

13. Lewis Structures

Valence electrons of a covalent bond –
bonding electrons
Valence electrons not involved in the covalent
bond – lone electron pairs(nonbonding)
Lewis structure – convenient representation of
bonding and nonbonding electrons in a
molecule

14. Lewis Structures

More than one Lewis structure for a molecule – resonance

15. Formal Charge

16. Formal Charge

17. Resonance structures

18. Types of covalent bonds

Polar covalent bonds – occurs between atoms
with small difference in electronegativity
Nonpolar covalent bond occurs between atoms
that have the same electronegativites
Coordinate Covalent Bond – the shared electron
pair comes from the lone pair of one of the
atoms in the molecules

19. Lewis acid and base

Lewis base NH3 – donor of pair if electrons
Lewis acid BF3 – acceptor of pair of electrons

20. Geometry and polarity

The Valence Shell Electron - Pair Repulsion Theory

21. Geometry and Polarity

22. Hybridization

sp – hybridization

23. Hybridization

24. Sigma and Pi bonds

25. Metallic bond

26. Summary

27. Summary

28. Summary

29. Summary