MOLECULAR ORBITALS
VSEPR cannot explain the bonding in all compounds Molecular orbital theory can
provide an explanation for more complex molecules
The molecular orbital approach is based on the idea that, as electrons in atoms occupy atomic orbitals,
electrons in molecules occupy molecular orbitals orbitals .
Molecular orbitals form when atomic orbitals combine. The number of molecular orbitals formed is
equal to the number of atomic orbitals that combine.
The combination of two atomic orbitals results in the formation of a bonding molecular orbital and an
anti bonding molecular orbital. The bonding orbital encompasses both nuclei. The attraction of the
positively charged nuclei and the negatively charged electrons in the bonding molecular orbital is the
basis between atoms.
Each molecular orbital can hod a maximum of two
electrons.
• In a non-polar covalent bond, the bonding molecular
orbital is symmetrical about the midpoint between two
atoms.
• Polar covalent bonds result from bonding molecular
orbitals that are asymmetric about the midpoint between
two atoms. The atom with he greater value for
electronegativity has the grater share of the bonding
electrons.
• Ionic compounds are an extreme case of asymmetry,
with the bonding molecular orbitals being almost entirely
located around just one atom, resulting in the formation of
ions.
VSEPR cannot explain the bonding in all compounds Molecular orbital theory can
provide an explanation for more complex molecules
The molecular orbital approach is based on the idea that, as electrons in atoms occupy atomic orbitals,
electrons in molecules occupy molecular orbitals orbitals .
Molecular orbitals form when atomic orbitals combine. The number of molecular orbitals formed is
equal to the number of atomic orbitals that combine.
The combination of two atomic orbitals results in the formation of a bonding molecular orbital and an
anti bonding molecular orbital. The bonding orbital encompasses both nuclei. The attraction of the
positively charged nuclei and the negatively charged electrons in the bonding molecular orbital is the
basis between atoms.
Each molecular orbital can hod a maximum of two
electrons.
• In a non-polar covalent bond, the bonding molecular
orbital is symmetrical about the midpoint between two
atoms.
• Polar covalent bonds result from bonding molecular
orbitals that are asymmetric about the midpoint between
two atoms. The atom with he greater value for
electronegativity has the grater share of the bonding
electrons.
• Ionic compounds are an extreme case of asymmetry,
with the bonding molecular orbitals being almost entirely
located around just one atom, resulting in the formation of
ions.
