Bonding Theories Section 16.2

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Bonding TheoriesSection 16.2

• Do not worry about the Molecular Orbitals!
• VSEPR Theory Valence Shell Electron Pair
  Repulsion Theory
• Electrons will repel each other, so that they are
  as far apart as possible
• Determines the shape of the atom, based on the
  number of bonding pairs of electrons and lone
  pairs of electrons

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Example of how VSEPR Theory works

Each bond will repel each other so that the atoms
are as far away as possible. CH4 (shown to the
left) is tetrahedral ( 4 bonding pairs, 0 lone
pairs) Lone pairs of electrons will push the
bonding pairs down, which changes the shape NH3
is trigonal pyramidal(3 bonding pairs and 1
lone pairs)
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Lone pairs and bonding pairs
Bonding pairs the number of elements bonded to
the central atom Oxygen is bonded to 2
hydrogen atoms, so it has 2 bonding pairs Lone
pairs the number of paired electrons on the
central atom that is not bonded to another
atom Oxygen is sharing all 4 electrons with
hydrogen, but it has 2 pairs of electrons that
are not bonded to another atom (2 lone
pairs)

• O C O
• O
• H H

Bonding pairs the number of elements bonded to
the central atom Carbon is bonded to 2 oxygen
atoms, so it has 2 bonding pairs Lone pairs
the number of paired electrons on the central
atom that is not bonded to another atom Carbon
is sharing all 8 electrons with oxygen,
therefore it has 0 bonding pairs
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After reading Section 16.2, you should know

• How to determine the number of bonding pairs and
  lone pairs of electrons on the central atom
• How to determine the shape of a given covalent
  compound