Structure & Bonding - overview
I. Intramolecular forces:
(& electronegativity)
-  Metallic bonding & alloys
-  Ionic bonding & formula units/salts
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Bond formation
Properties
Names & formulas
-  Covalent bonding & molecules
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II.
Lewis Dot Diagrams & Structures
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III.
Bond formation (including; types, strength, length, & Energy)
Properties
Names & formulas
Octet Rule
Bonding & Non-bonding electron pairs
Exceptions to octet
Resonance
VSEPR theory
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Molecular Geometry Names & Shapes
Bonding angles
Polarity (molecules & bonds)
Hybridization
Chemical Bonds are forces of attraction between elements.
-  Bonds that form compounds are called intra-molecular
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forces.
Bonds that form between 2 different compounds are called inter-molecular
Example of chemical bonding 
forces.
1. Intra-molecular Bonds
(occur inside a compound)
–  Are the Chemical Bonds or Forces that hold elements together, forming compounds.
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- There are 3
main types of intramolecular bonding forces, in decreasing strength.
1. Ionic bonds, form ionic compounds (formula unit).
2. Metallic bonds, form metallic compounds (alloy).
3. Covalent bonds, form covalent compounds (molecule).
Metallic Bonds hold Alloy’s together.
-  2 or more metal elements bonded together, are called an “Alloy” or
“metallic compound”.
-  Alloy’s are held together by delocalized electrons, that are able to move throughout (3-D) the
metal atoms, and not attracted to any specific atom, called the “electron sea model”.
(Delocalized electrons are the cause for magnetism)
Intramolecular Bond Types:
1. Ionic bond (compounds)
 If the Electronegativity difference is equal
to or greater than 1.7
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2.  Covalent Bonds (compounds)
a. Polar Covalent bonds
 If the Electronegativity difference is between 1.7
 0.5 (& equal to 0.5)
b. Nonpolar Covalent bonds
 If the Electronegativity difference is
less than
0.5
- Ionic Bonds (form ionic compounds, called “Formula Unit” or “Salt”)
- Is a strong attractive force between Cation (metal) + Anion (non-metal).
- One element gains an electron and one element loses an electron called “transfer”.
(ionic bonds are stronger than covalent & metallic bonds.)
Example:
Ionic Compound Properties:
•  Are Hard & Brittle with high melting and boiling points.
•  Ionic solids form crystal lattice structures.
•  Are Soluble(dissolves) in water, but insoluble( doesn't dissolve) in organic solvents (like oil or alcohol).
•  Conduct electricity when molten or aqueous, called an “electrolyte”
A Crystal Lattice is a tightly packed geometric arrangement of formula units.
- Lattice Energy is needed to break the force of attraction between the (+) and (-) ions arranged in a crystal lattice.
- This lattice energy is why ionic compounds are so strong (high melting & boiling pts.)
- Electrolyte is any compound that conducts electricity when melted or dissolved in water (aqueous).
- An ionic compound is an electrolyte because it conducts an electric current when it is dissolved in water, producing ions
(+) and ( - ).
Sodium chloride in solution
NaCl
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Covalent Compounds
Also called
“Molecular compounds”
also called
“molecules”
Properties include:
•  Are usually soft, and easily deformed. (like silly putty)
•  Mainly Gases or Liquids at room temperature.
•  Molecules have low melting points, low boiling points.
•  Tend to be insoluble in water, but will dissolve in organic solvents.
•  Do not conduct electricity in water (poor electrolytes).
Allotropes are forms of an element in the same state (Solid, Liquid),
that have different structures(arrangements) & properties.
Coal
Graphite
Diamond, are all
carbon compounds.
A molecular compound is a molecule, held together by a covalent bond.
A molecule forms when 2 atoms
Share a pair of electrons.
1. Single bond = weakest strength + longest length.
- Are one bond formed from sharing 2 electrons.
Example
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2. Double bond = medium strength + medium length.
- Are two bonds formed from sharing 4 electrons.
Example
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3. Triple bond = strongest strength + shortest length.
- Are three bonds formed from sharing 6 electrons.
Example
The longer the bond length, the weaker it is and less energy is needed to break it.
The shorter the bond length, the stronger it is and more energy is needed to break it.
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Energy is absorbed when bonds break, and energy is released when bonds form.
(endothermic)
(exothermic)
•  The amount of energy required to break a covalent bond is called the bond
“Dissociation Energy”
(always (+) value).
•  Sigma bonds are Single bonds
(ALWAYS the 1st bond formed)
- involve the S orbital’s.
•  Pi bonds are double or triple bonds (the
- involve
2nd & 3rd bonds to form between same two atoms).
P orbital’s, overlapping above and below sigma bonds.
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Covalent Bond Types
 can be polar or
non-polar
- Non-polar bonds have an electronegativity difference equal or less than 0.4
- Polar bonds have an electronegativity difference greater than 0.4 and less than 1.7
Labeling
Polar Bonds
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- The more electrically negative element is labeled …..
- The more electrically positive element is labeled …..
Example:
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(is the entire molecule polar or nonpolar)
Molecular Polarity
1. Asymmetrical,
is determined by …
meaning the central atom has additional non-bonding electrons.
(Binary molecules = uneven electron distribution)
2. has Polar Bonds between the atoms.
Example 