Thematic Unit
Introductory Paragraph
The theme of this unit is Molecular Shapes and Covalent Bonds. On Day 1, we
introduced Covalent Bonding and electron dot structures. We referred back to prior
learning on the topics of Ionic Bonding and chemical formulas, taking advantage of 3D
models that the students used to discover for themselves how the atoms in a molecule
might bond together (this was starting with the application). We compared and
contrasted the 2 types of bonding, using a rich variety of language to inform students’
understanding of them. We used Teach the Text Backwards and Think-Pair-Share (and
guided discussion) as strategies to address the 3 principles of sheltered instruction on the
first day. We also began to teach them step-by-step how to draw/represent molecules
using Electron Dot Structures. We explored language by making comparisons and
activating prior knowledge regarding “covalent,” “notation,” “ionic,” “octet,” and
“sharing” vs. “giving and taking.”
On the second day, we introduced the students to more advanced molecular structures
and the idea of bond order, using guided discussion, models and guided notes. We had
time for the students to practice using the steps outlined on day 1 to draw/represent
additional molecules. Think-Pair-Share was utilized on several occasions, as was Teach
the Text Backwards for each section of this unit. On the third day, we introduced the
shapes (molecular geometry). We used different colored balloons to represent the
electrons in each bond. Balloons were added to signify more-complicated molecules, and
students drew on known language to make connections to the new geometrical-shape
vocabulary being introduced. We used guided discussion, guided notes, models, and
practice problems. Embedded in Day 2 and 3 was the vocabulary from Day 1 and new
vocabulary such as “pyramid,” “linear,” and “planar.” Prior knowledge was activated
with words such as “tri-,” “tetra-,” “bi-,” and “oct-.”
Student Composition
Grade level – 11
Native Language – Arabic
Proficiency Level – Transitional
Number students at Transitional Level – 1
Unit Graphic Organizer
Ionic
Valence Electrons
Covalent
Octets
Molecular Shapes
and Bonds
Shapes / Molecular
Geometry
Lewis Dot Structures
Bond Order / Strength / Length
Resonance
Lesson Plan Format
1. Preparation Before Class
Standard/s:
Content Area Curriculum Frameworks:
ELPBO:
Objectives: Students will be able to (finish with active verbs)
Content: Massachusetts Curriculum Learning Standards – High School Chemistry
4.1 Explain how atoms combine to form compounds through both ionic
and covalent bonding. Predict chemical formulas based on the number of
valence electrons.
4.2 Draw Lewis dot structures for simple molecules and ionic compounds.
4.4 Use valence-shell electron-pair repulsion theory (VSEPR) to predict
the molecular geometry (linear, trigonal planar, and tetrahedral) of simple
molecules.
Language:
Learning Strategies:
Think-Pair-Share
Teach the Text Backwards
Key Vocabulary: (list)
ionic, covalent, metallic, bond, octet, sharing, pyramid, linear, planar, bi-, tri-, tetraKey Grammatical Structures/Uses of Language: (list)
Materials, Texts, and/or Other Resources: (list)
Model kits
Addison-Wesley textbook
Guided notes
Balloons
Lesson Plan Graphic Organizer Day 1 (lesson 1)
Three-column chart comparing and contrasting ionic, covalent and metallic bonds &
compounds. Even though this unit focuses on covalent bonds & molecules, prior
knowledge of ionic & metallic bonds is drawn on to complete the chart.
Ionic
Covalent
Metallic
Relative Melting
High
Low
High
point/boiling point
Electrical
molten state or
None
solid state
conductivity
aqueous solution
Appearance
crystalline solids
can be any phase of Lustrous, ductile,
matter
malleable
Solubility in water
Soluble
insoluble
insoluble
(in general)
General types of
Metal & non-metal
2 Non-metals
2 Metals
atoms involved
Lesson Plan Graphic Organizer Day 2 (lesson 2)
Three-column chart relating bond energy, bond length and bond order.
Bond
Bond Energy (kJ/mol)
Bond Length (pm)
Bond Order
C–C
347
154
1
C=C
657
133
2
C≡C
908
121
3
Lesson Plan Graphic Organizer Day 3 (lesson 3)
Chart relating steric number to molecular geometries. Images are also included to show
visual examples of each geometry, in addition to new vocabulary.
Steric
Number
1
# of Atoms
Connected to
Central Atom
1
Molecular
Geometry
linear
Example
Formula(s)
H2,F2
Image of example
H–H
2
3
2
3
linear
trigonal planar
BeCl2
BF3
4
4
tetrahedral
NH4+
3
trigonal pyramidal
NH3
2
bent
NH2-
5
5
trigonal bipyramidal
PF5
6
6
octahedral
IF6+
Rubric for lab
Criteria
Physically
build the
models
4 - Exemplary
• 100% Accuracy
• No missing
bonds/electron pairs
• Correct color of
beads (atoms)
3 – Proficient
• One missing
bonds/electron
pair
• Correct color
of beads
(atoms)
Correct
Electron
dot
structures
(drawings)
• Total number of
valence electrons
represented
• Each atom has a full
octet (if applicable)
• Connectivity of
atoms correct
(central atom chosen
correctly)
• All characteristics of
specific atoms are
represented correctly
(i.e. no double bonds
with halogens or
hydrogen)
• Total number
of valence
electrons
represented
• Each atom has
a full octet (if
applicable)
• Connectivity
of atoms
correct (central
atom chosen
correctly)
• Some
characteristics
of specific
2 - Developing
• Several
missing
bonds/electro
n pairs
• Correct color
of beads
(atoms)
• Total number
of valence
electrons
represented
• Some atoms
lack a full
octet
• Connectivity
of atoms
correct
(central atom
chosen
correctly)
• Several
characteristics
1 - Beginning
• Several missing
bonds/electron
pairs
• Incorrect color
of beads (atoms)
Points
____ X 2
• Total number of
valence electrons
represented
incorrectly
• Some atoms lack
a full octet
• Connectivity of
atoms incorrect
(i.e. central atom
chosen
incorrectly)
• Many
characteristics of
specific atoms
are represented
____ X ½
per structure
atoms are
represented
incorrectly (i.e.
double bonds
with halogens
or hydrogen)
Molecular
shapes
• Correct geometric
shape chosen for
molecule
• Accurate threedimensional sketch
illustrating location
of atoms
• Correct
geometric
shape chosen
for molecule
of specific
atoms are
represented
incorrectly
(i.e. double
bonds with
halogens or
hydrogen)
• Incorrect
geometric
shape chosen
for molecule
incorrectly (i.e.
double bonds
with halogens or
hydrogen)
• Incorrect
geometric shape
chosen for
molecule
____ X ½
per molecule