Unit 7: Chemical Bonding
Chemistry
Video #1: Valence Electrons
What are valence electrons?
the outermost energy level/shell that are most likely to be involved in chemical bonding
How do you know the number of valence electrons an element has?
Group #
# Valence e-
1
2
13
14
15
16
17
18
1
2
3
4
5
6
7
8 (except
He)
What are chemical bonds and why do they occur?
electron configuration like the noble gases. Simply put, atoms want to look like noble gases, which have 8 valence
electrons. This is referred to as the octet rule.
PRACTICE QUESTIONS:
1. What type of electrons are involved in bonding?
Valence electrons (s and p electrons)
2. What rule explains why atoms want to form bonds?
Octet Rule
3. Why do group 18 elements not want to bond with other elements?ements wnt to form bonds so that they can look
like the noble gases.
4. How many more electrons does fluorine need to be full?
1
5. How many more electrons does phosphorus need to be full?
Vocabulary
Things to Memorize
Formulas
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3
Questions for the Teacher
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Unit 7: Chemical Bonding
Chemistry
Video 2 : Lewis Dot Structures
_______________________ Electrons
 In the outermost energy level (or shell)
 Most likely to be involved in _______________________
 Helpful in predicting _______________________ numbers (charge within a compound)
The noble gases are considered to be _______________________, so their outer shell is _______________________.
Steps for drawing Lewis Dot Structures:
1.
2.
3.
Problem 11: Draw the Lewis Dot Structures for the following elements.
K
Al
P
C
Cl
Kr
Problem 12: Complete the following questions.
a. How many valence electrons does sulfur have?
b. Draw the Lewis Dot Structure for sulfur.
c. How many valence electrons does sodium have?
d. Draw the Lewis Dot Structure for sodium.
Vocabulary
Things to Memorize
Formulas
Page 2 of 10
Questions for the Teacher
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Unit 7: Chemical Bonding
Chemistry
In class notes Video 1 and 2 :
Main Ideas
Notes Taken during class: Make sure to leave space in between topics/videos!
Summary ( Done after class)
Page 3 of 10
Unit 7: Chemical Bonding
Chemistry
Video #3: Ionic Bonds
What is an ionic bond?
Ionic bonds can occur between…
What elements are going to be cations?
The properties of ionic compounds are…
Cations are
 Not discrete molecule
 a solid crystal stferred to as “sa
Examples of ionic compounds include…
What elements are going to be anions?Anions are
Sodium chloride (table salt)
Sodium fluoride (the “fluoride” source in toothpaste)
DRAWING IONIC LEWIS STRUCTURES
*The overall charge in a compound must equal ___________________.
*Cations wind up with a positive charge and no dots inside the brackets.
*Anions wind up with a negative charge and 8 dots inside the brackets.
EXAMPLES:
Draw the Lewis Dot Structures for the
following ionic compounds.
PRACTICE PROBLEMS:
Draw the Lewis Dot Structures for the following ionic
compounds.
1. Sodium and Chlorine
1. CaCl2
4. Li2O
2. Magnesium and Oxygen
2. KBr
5. NaF
3. Al2S3
6. MgI2
3. Magnesium and Chlorine
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Unit 7: Chemical Bonding
Chemistry
Vocabulary
Things to Memorize
Formulas
Questions for the Teacher
In class notes Video 3:
Main Ideas
Notes Taken during class: Make sure to leave space in between topics/videos!
Summary ( Done after class)
Page 5 of 10
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Unit 7: Chemical Bonding
Chemistry
Video #4: Metallic Bonding
What is a metallic bond?
when metal atoms donate their valence electrons into a “sea” of electrons.
Where are metallic bonds found?
Delocalized electrons are…
Metals are tough and have a high melting point because…
…
Metals are ductile and malleable because…
…
Metals are good conductors of electricity because…
Metals are good conductors of heat because…
…the delocalized electrons can transmit kinetic energy rapidly. Heat, or thermal energy, is a type of kinetic energy, which
is the energy of moti
A. The “sea” of delocalized electrons
B. Electrons move in the same
direction in response to an
electrical field to conduct electricity
C. Delocalized electrons conduct
kinetic energy rapidly
D. Layers of atoms are able to slip past
each other easily
Vocabulary
Things to Memorize
Formulas
Page 6 of 10
Questions for the Teacher
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Unit 7: Chemical Bonding
Chemistry
Video #5: Covalent Bonding and VSEPR Shapes
What is a covalent bond?
A double bond occurs when…
g of
Properties of covalent compounds include…

A triple bond occurs when…
Discrete molecules
A lone pair is…
The central atom is…
A single bond occurs when…
Steps to drawing Lewis Structures for Covalent Bonds.
1. Determine the type and number of atoms in the molecule.
a. of electrons.
b. Repeat steps 5a and 5b if necessary.
EXAMPLES:
Cl2
NH3
CO2
HI
H2O
SiO2
NCl3
O2
BCl3
CCl4
N2
OF2
PRACTICE PROBLEMS:
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Unit 7: Chemical Bonding
Chemistry
Vocabulary
Things to Memorize
Formulas
Questions for the Teacher
In class notes Video 4 and 5:
Main Ideas
Notes Taken during class: Make sure to leave space in between topics/videos!
Summary ( Done after class)
Page 8 of 10
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Unit 7: Chemical Bonding
Chemistry
Video #6: VSEPR Theory (Molecular Geometry)
What do Lewis Structures not tell us?
nce Shell Electron Pair Repulsion
What is the VSEPR Theory?
Wha
t molecules actually look like in 3-D space.
What does VSEPR stand for?
The VSEPR Theory states that the geometry or shape of
Vale
How do I determine the shape of a molecule?
Use the AXE formula:
A = central
X = # of atoms bonded to the central atomE = # of lone pairs on the central ato
AXE Formula
VSEPR Shape
Examples
AX
AX2
AX3
AX4
AX3E
AX2E2
Linear
Linear
Trigonal Planar
Tetrahedral
Trigonal Pyramidal
Bent
Cl2, HI
CO2, SiO2
BF3
CH4, SiCl4
NH3, PCl3
H2O, OF2
*Look at the structures you drew for video 4. Write the AXE formula and determine the shape of each molecule.*
EXAMPLES:
Cl2
AX
Linear
NH3 AX3E
Trigonal Pyramidal
CO2
Linear
AX2
PRACTICE PROBLEMS:
HI
AX
Linear
H2O AX2E2
Bent
SiO2
Linear
AX2
NCl3
AX3E
Trigonal Pyramidal
O2 AX
Linear
BCl3
Trigon
AX3
N2 AX
Linear
OF2
al Planar
CCl4
AX4
Tetrahedral
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Bent
AX2E2
Unit 7: Chemical Bonding
Chemistry
Vocabulary
Things to Memorize
Formulas
Questions for the Teacher
In class notes Video 6:
Main Ideas
Notes Taken during class: Make sure to leave space in between topics/videos!
Summary ( Done after class)
Page 10 of 10
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