A sodium atom forms a cation by losing an electron, attaining a stable noble gas configuration. A chlorine atom gains this electron to form the anion, also achieving a stable noble gas configuration. The attraction between the oppositely charged sodium and chlorine ions leads to the formation of an ionic solid, NaCl, which has a crystal structure and represents the lowest energy state.

1. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 1
Ionic Bond
Na([Ne]3s1
) + Cl([Ne]3s2
3p5
) Na ([Ne]) + Cl ([Ne]3s2
3p6 _
[Ar] in fact)
cation anion
Noble gas
configuration
Noble gas
configuration
A sodium atom loses an electron from its last shell and forms a cation. The cation, now,
has the neon configuration, [Ne]. This configuration is very stable since it corresponds
to a noble-gas configuration. The chlorine atom, on the other hand, receives the
electron from the sodium atom, itself attaining the argon configuration [Ar]. This
configuration is also very stable, corresponding to a noble-gas configuration.
It is the stability of the ions that ultimately lead to the formation of the ionic solid,
NaCl. Once a cation or an anion is formed, it starts to attract oppositely charged ions
immediately. This attraction improves stability furthermore, attaining the crystal
structure ultimately. The ionic solid represents the lowest energy level, and therefore
maximum stability.

2. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 2
Covalent Bond

3. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 3
Orbitals in Covalent Bond

4. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 4
Bond Energies

5. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 5
Lewis Dot Symbols
Each element is shown by its elemental symbols and valence
electrons only

6. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 6
::H Cl
:: 1bonding pair
3 lone pairs
When the atoms combine, they form a stable covalent bond. This
bond is a single bond, denoted by a single line between the two
atoms. Each single bond represents a pair of electrons. By sharing
a pair of electrons, hydrogen is surrounded by two and chlorine is
surrounded by eight valence electrons.
Formation of Hydrogen Chloride
H Cl

7. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 7
Electronegativities of Elements

8. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 8
Formation of Hydrogen Fluoride

9. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 9
Interference of Waves
Constructive
Destructive

10. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 10
Shapes of Orbitals

11. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 11
Structure of Methane

12. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 12
sp3 Hybridisation

13. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 13
Common Hybridisations

14. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 14
Arrangement of Electron Pairs

15. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 15
Molecular Shapes

16. Chemical Bonding and Molecular Structure
General Chemistry CHM 107 Dr Erdal Onurhan Slide 16
Molecular Shapes