1
Cornell Topic/Objective: Name:
Notes
Chapter 2: Chemical Bonding Class/Period: Chem 121 111
and Lewis
Date: 09/24/2022
Essential Question:
Keywords: Notes:
Resonance Several ways of expressing the structures of a molecule based on their electron
Structures composition
Hypervalence An expanded octet (more than 8 electrons)
A molecule with 2 or more atoms that have different electron negativity, where one
Polar Covalent bonds is PULLED towards another
Non-polar bonds A molecule of the same element or similar electronegativity
Ionic bonds Transferring of electrons USUALLY between a metal and non-metal
- Bond order correlates with the number of bonds.
Bond Order (Eg. 1st order = Single bond, 2nd order = Double Bond)
- Energy to break a bond (or more)
Bond Dissociation Usually given in a value kJ/Mol
Order (BDO)
Ionic/polar & non-polar covalent bonds
Ionic compounds undergo redox reactions, unlike polar covalent bonds, were one atom is pulled to the more
electronegative one
(Redox reaction is when one is oxidized (looses electrons) and the other reduced (gains electrons)
Example:
Ionic compounds
.
Polar covalent I na I [ a
]
, 2
It Means partially positive
Polar covalent dt dt
o Means partially negative
H
-
-
+ ◦
d-
¥
Hydrogen is pulled towards oxygen
How to Associate Bond order, Bond Dissociation Energy (BDE) and Bond Length?
Bond Order 1 2 3
Bond Length Furthest Mid Closest
BDE Least Mid Most
• The lower the order the further the length. There is less energy to keep it tight and close.
• The lower the order the lesser energy it takes to break a bond. Their bond is weaker
Bond Dipole
Example:
dt 1 A d-
H -
CI
When one (or more) atoms in a molecule are PULLED towards more
electronegative atom.
Octet Rule
An atom has to satisfy the octet rule of 8 valence electrons (Outer shell
electrons)
Exceptions (some don’t follow the octet rule):
• Group 13 elements can have less than 8
• Elements in the 3rd row and below of the P block can go into
hypervalence
• Free Radicals (unpaired electrons, often seen in uneven number total
valence electrons in a molecule)
Cornell Topic/Objective: Name:
Notes
Chapter 2: Chemical Bonding Class/Period: Chem 121 111
and Lewis
Date: 09/24/2022
Essential Question:
Keywords: Notes:
Resonance Several ways of expressing the structures of a molecule based on their electron
Structures composition
Hypervalence An expanded octet (more than 8 electrons)
A molecule with 2 or more atoms that have different electron negativity, where one
Polar Covalent bonds is PULLED towards another
Non-polar bonds A molecule of the same element or similar electronegativity
Ionic bonds Transferring of electrons USUALLY between a metal and non-metal
- Bond order correlates with the number of bonds.
Bond Order (Eg. 1st order = Single bond, 2nd order = Double Bond)
- Energy to break a bond (or more)
Bond Dissociation Usually given in a value kJ/Mol
Order (BDO)
Ionic/polar & non-polar covalent bonds
Ionic compounds undergo redox reactions, unlike polar covalent bonds, were one atom is pulled to the more
electronegative one
(Redox reaction is when one is oxidized (looses electrons) and the other reduced (gains electrons)
Example:
Ionic compounds
.
Polar covalent I na I [ a
]
, 2
It Means partially positive
Polar covalent dt dt
o Means partially negative
H
-
-
+ ◦
d-
¥
Hydrogen is pulled towards oxygen
How to Associate Bond order, Bond Dissociation Energy (BDE) and Bond Length?
Bond Order 1 2 3
Bond Length Furthest Mid Closest
BDE Least Mid Most
• The lower the order the further the length. There is less energy to keep it tight and close.
• The lower the order the lesser energy it takes to break a bond. Their bond is weaker
Bond Dipole
Example:
dt 1 A d-
H -
CI
When one (or more) atoms in a molecule are PULLED towards more
electronegative atom.
Octet Rule
An atom has to satisfy the octet rule of 8 valence electrons (Outer shell
electrons)
Exceptions (some don’t follow the octet rule):
• Group 13 elements can have less than 8
• Elements in the 3rd row and below of the P block can go into
hypervalence
• Free Radicals (unpaired electrons, often seen in uneven number total
valence electrons in a molecule)
