Topic
6
Bonding
Energy and Chemical Bonds




Bonds are _______________________ that hold atoms together in a compound.
__________________ is required to overcome these _______________ and break a bond.
Therefore, breaking a bond is an _________________________ process.
Likewise, forming a bond is an ______________________ process.

Since energy is released when a bond is formed, a compound always has ____________ potential energy than
its components.

The more energy released when a bond is formed, the more _____________ the compound is.
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Topic
6
Bonding
Lewis Electron Dot Structures


A Lewis dot diagram consists of a _________________ ____________________ surrounded by its
___________________ electrons.
The symbol of the element represents the element’s ______________________ and its ______________
___________________________. This is called the _______________________.

To draw a Lewis dot diagram for a neutral atom, the first two electrons are __________________. Then,

follow the “bus seat” rule.
The maximum number of valence electrons is _______________.

To draw a Lewis dot diagram for an ion, use brackets. [ ]

Metals _____________ electrons when they form ions, so metal ions will have _______ valence electrons to
draw. Write the ion’s charge in the upper right outside the bracket.
o Ex.) Draw the Lewis dot diagram for a sodium ion:
Draw the Lewis dot diagram for a calcium ion:

Nonmetals ___________ electrons when they form ions, so nonmetal ions will have ___________ valence
electrons than the neutral atom. Also draw brackets [ ], the total number of ionic electrons, and the charge
outside the upper right of the brackets. You can use an open dot for the gained electrons.
o Ex.) Draw the Lewis dot diagram for a chlorine ion:
Draw the Lewis dot diagram for an oxygen ion:
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Topic
Bonding
6
Lewis Electron Dot Diagrams of Compounds
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
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Lewis dot diagrams can be used to predict and show ________________, __________________, and
____________________ covalent bonds.
Each atom is most stable when it has ____________________ electrons in its valence shell. (Except hydrogen
only can have _______.)
For example, the Lewis structure of one hydrogen atom is ___________. It needs one more electron to fill its
outer shell. Two hydrogen atoms can share their electrons, so that each has a full outer shell:

A line can be drawn for each pair of shared electrons:

Draw the Lewis structure for one chlorine atom:
H ____ H
H -- H
How many more electrons does a chlorine atom need to have a full outer shell? _____
Draw two chlorine atoms sharing electrons so that they both have a full outer shell:


Remember that oxygen is a diatomic element. That means that it only exists in nature as ______________.
Draw the Lewis structure for one oxygen atom:
How many electrons does it need to have a full outer shell? _____
Two oxygen atoms will share two pairs of electrons, called a double covalent bond. Draw O2:

Nitrogen is unique because it forms a triple covalent bond when it is in its natural diatomic form. Draw N2:
MEMORIZE THIS
All covalent compounds (nonmetals bonded with other nonmetals) can be drawn with Lewis models by following these
rules:
1. _______________ only can form one single covalent bond.
2. All other atoms will need to fill their valence shells with ___________ electrons. Remember that a bond
represents a__________ of electrons.
3. Carbon always forms 4 covalent bonds. This can be any combination of single, double, and/or triple.
4. The atom with the lowest electronegativity goes in the middle.
5. Other atoms surround the central atom.
6. Don’t be afraid of trial and error.
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Topic
6
Bonding
Metallic Bonds
Metallic atoms have ________ valence electrons. They also have ________ ionization energies.
However, the bonds between metallic atoms must be very ______________ because metals have high
_______________________ and _____________________ points.
How are the kernels of metallic atoms arranged?
______________________________________________________
______________________________________________________
Describe how the valence electrons move:
________________________________________________________
Remember:
What is a kernel?
____________________________________
____________________________________
____________________________________
____________________________________
____________________________________
________________________________________________________
What does a metallic bond result from? _______________________________________________________________
________________________________________________________________________________________________
What is malleability? ______________________________________________________________________________
What is forced to move when a metal is hammered? ____________________________________________________
What do the valence electrons do when a metal is hammered? ___________________________________________
What is a “Sea of Mobile Electrons”? _________________________________________________________________
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Topic
6
Bonding
The Octet Rule
Define octet:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Why are noble gases so very stable / unreactive?
__________________________________________________________________________________________________
__________________________________________________________________________________________________
Why do all other atoms strive for eight valence electrons?
MEMORIZE THIS
__________________________________________________________________________________________________
__________________________________________________________________________________________________
What two elements have a full valence shell with only 2 electrons? ______________________ and _________________
State the octet rule:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
5
Topic
6
Bonding
Covalent Bonds
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
MEMORIZE THIS
Form between nonmetals and other nonmetals!
Because the electronegativity values are the same or have a small difference.
Term
Definition
Lewis Dot diagram
Stick diagram
covalent bond
nonpolar covalent bond
Group _____
diatomic molecules
multiple covalent bond
double covalent bond
triple covalent bond
polar covalent bond
unequal
______________________
values
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Topic
6
Bonding
Molecular Substances
A molecule is formed by ___________________ bonded atoms.
May exist as _________________, _____________________, or ______________ depending on the strength of the
forces of ____________________ between the molecules.
Properties associated with molecules and covalent bonds:
1. __________________________
2. ___________________________________________________________________
3. ___________________________________________________________________
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
Even though a molecule contains polar bonds, if the molecule is shaped _______________________________, then
the whole molecule is nonpolar.
A molecule with an asymmetrical shape is ________________ overall.
Fill in the chart. You need to memorize these molecules for shape and polarity.
name
molecular formula
structural formula
polar molecule or
nonpolar molecule
hydrogen
water
ammonia
carbon dioxide
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carbon
tetrachloride
(This is true for
any C X 4)
hydrogen
chloride
(hydrochloric
acid)
Draw the electron sharing for each type of bond:
Nonpolar covalent:
Polar covalent:
Ionic:
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Topic
6
Bonding
Ionic Bonding
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
MEMORIZE THIS
Ionic bonds form between a metal and a nonmetal,
because their electronegativity values have a large difference.
Ionic bonds form when ions bond together due to electrostatic _____________________ between ________________
charged ions.
Complete the chart for metals and nonmetals forming ions:
Metal ion
MEMORIZE THIS
Nonmetal ion
gain or lose electrons
charge
relative size of radius
electron
configuration
Explain how an atom follows the octet rule when it forms an ion:
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
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Define Electronegativity: __________________________________________________________________________
__________________________________________________________________________________________________
Which Reference Table contains electronegativity values? _________
Draw 5 atom cards, and look up the electronegativity value for each:
Element
electronegativity
If the electronegativity values between two atoms is
__________ or greater, the bond will be ionic.
Therefore, if the electronegativity difference is less than
____________, the bond will be _____________________.
MEMORIZE THIS
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Topic
Bonding
6
Distinguishing Bond Types
Bond Type
Type of atoms
metallic
metals only
covalent
nonmetal(s) + nonmetal(s)
ionic
nonmetal + metal
melting and
boiling points
hardness
solid
Conductivity
liquid
aqueous
MEMORIZE THIS
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Topic
6
Bonding
Intermolecular Forces
What is a dipole?
__________________________________________________________________________________________________
__________________________________________________________________________________________________
What are dipole-dipole forces?
__________________________________________________________________________________________________
__________________________________________________________________________________________________
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
Sketch an ammonia molecule, and label the positive and negative ends to show that it is a dipole.
Sketch a second ammonia molecule near the first to show dipole-dipole forces.
Hydrogen Bonding
MEMORIZE THIS
A hydrogen bond is an attractive force between a _____________________ atom in one molecule and a
_________________________, ______________________, or ____________________ atom in another molecule.
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Hydrogen bonds are much ___________________ than dipole-dipole forces.
Hydrogen bonds account for the abnormally high ______________________ of water.
Nitrogen, oxygen, and fluorine have high ________________ and small _____________________.
Draw three water molecules, and show the hydrogen bonds between them:
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