Lewis Structures Unit
October 19- 30 (2015)
Day 1: Ionic Compound Drawing
Objectives (SWBAT):
Physical Science 23- Model chemical bond formation using Lewis dot diagrams for ionic compounds
Physical Science 5- Write formulas for ionic compounds
Evaluated by:
Ionic Bonding Worksheet
Class structure:
Do Now: What ion will calcium form? Fluorine?
1. Engage- The teacher will draw ion formation on the board and tie it back to ion and ionization energy
definitions.
2. Explore- Students will draw ionic bond formation and predict ions present in a compound by showing
electron transfer with Lewis Dot diagrams.
3. Explain- Students will use their diagrams to write the formula for the ionic compounds they’ve drawn.
4. Elaborate- Students will continue their drawing practice individually with a homework sheet.
Summary: Ions are formed by a gain or loss of electrons. This transfer of electrons creates a bond between the two
elements called an ionic bond.
Day 2: Crisscross Formula Writing
Objectives (SWBAT):
Physical Science 16- Predict the ion formed by selected elements
Physical Science 23- Model ionic bond formation with Lewis Dot structures
Physical Science 5- Use oxidation numbers to write formulas for ionic compounds
Evaluated by:
-Element Quiz #1-36
-Crisscross Worksheet
Class structure:
Do Now: What is the formula when Mg and P form an ionic bond?
1. Engage- One group will draw the ionic bond formation from the Do Now on the board. Another group
will give the charges of the ions. A third group will provide the formula for the compound formed. The
teacher will connect these things to introduce the crisscross method.
2. Explore- Students will use the crisscross method to find the formulas for 88 compounds.
3. Explain- Students will show all their work for the crisscross method.
4. Elaborate- Students will draw out the first the calcium compounds on the back of the page to check their
work.
5. Evaluate-With the last ten minutes of class, students will number a paper 1-15 and complete the second
element quiz.
Summary: A simple way to write the formula for an ionic compound is to find the oxidation number of each ion and
crisscross them to find the subscript (or number of atoms) of the matching ion needed. Be sure not to include charges in
the subscripts and if an ion is polyatomic, it MUST be in parenthesis before the crisscross.
Day 3: Preparing a Lab Write-up
Objectives (SWBAT):
Physical Science 23- Model ionic bond formation with Lewis Dot structures
Inquiry 3 and 6- Plan and record step-by-step procedures for a valid investigation; choose appropriate materials; identify
safety concerns
Evaluated by:
Pre-Lab for the Ionic Compound Properties
Class structure:
Do Now: Write the formula for the bond made by sodium and phosphorus.
1. Engage- Students will brainstorm as a class the physical and chemical properties of metals and
nonmetals then predict properties of ionic compounds.
2. Explore- Students will read through the lab and prepare a lab write-up including the objective, materials
list, safety concerns, and a step-by-step procedure for day 4’s lab.
3. Explain- Students will explain why each safety procedure is necessary.
4. Elaborate- Students will read section 7.2-7.3 in the text and take notes as the pre-lab.
Summary: Properties of compounds are different than properties of the component elements. Ionic compounds are
crystalline, solid at room temperature, and very strong.
Day 4: Properties of Ionic Compounds Lab
Objectives (SWBAT):
Physical Science 14- Measure and compare the properties of ionic compounds
Inquiry 3 and 6- Use a multimeter to determine conductivity; write and defend a conclusion based on experimental data
Evaluated by:
Properties of Ionic Compounds Lab
Class structure:
Do Now: In your groups, assign one person per task- goggles, aprons, label 4 test tubes, meet with teacher for
safety review.
1. Engage- The teacher will demonstrate how to use a multimeter.
2. Explore- Students will complete the steps of the lab and record observations on appearance, structure,
solubility, conductivity, and relative melting points.
3. Explain- Students will analyze data to draw conclusions about the properties of ionic compounds.
4. Elaborate- The students will compare their results to a covalent compound that is solid at room
temperature (table sugar). The teacher will then tie the properties of ionic compounds to their
structure (ionic bonding is VERY strong).
Summary: Ionic compounds organize themselves into orderly crystals. These crystals easily dissolve in water where they
separate into ions that conduct electricity. Ionic compounds are also composed of strong bonds that result in high
melting points.
Day 5: Metallic Bonding
Objectives (SWBAT):
Physical Science 14-differentiate between alloys and pure metals based on physical and chemical properties
-describe metallic bonds and how they are formed
-explain how the properties of metallic bonds are related to their structure
Evaluated by:
-Element Quiz #1-54
-Notes and answers from textbook section 7.3
Class structure:
Do Now: Explain whether the properties of ionic bonds are most similar to metals, nonmetals, or neither.
1. Engage- Students will number a sheet of paper from 1 to 25 and complete the last element quiz.
2. Explore- Students will read section 7.3 in the textbook and take notes.
3. Explain- Students will answer questions 20, 21, 24, 25, 26, 48, and 50 in the textbook section they took
notes on.
4. Elaborate- The class will participate in the sea of electrons activity and the teacher will tie this structure
of metallic bonds to the properties students read about.
Summary: Valence electrons in pure metals can be modelled as a sea of electrons which explain the physical properties.
Alloys are homogeneous mixtures of metals with different physical properties than their substituent metals.
Day 6: Covalent Drawing
Objectives (SWBAT):
Physical Science 23- Model covalent bond formation using Lewis Dot diagrams (ball-and-stick modelling)
Physical Science 5- Write formulas for covalent bonds from drawings
Physical Science 9- Identify the number of bonds an atom can form given the number of valence electrons
Physical Science 13- Draw Lewis Dot diagrams (ball-and-stick models) for single, double, and triple bonds, as well as for
diatomic molecules
Evaluated by:
-Covalent Bonding Intro
Class structure:
Do Now: Name two elements that will form an ionic bond with each other. Name two elements that will form a
metallic bond. (Teacher will then remind students of the names for these compounds- salts and alloys)
1. Engage- Students will complete problem one on the worksheet for the day as a review of atomic
structure and the Bohr model.
2. Explore- Students will draw the Lewis Dot diagrams for the elements listed in question two by working
to fill each element’s valence shell.
3. Explain- Students will write the formula for each of the compounds drawn in question two then draw
the bond formations of eight new formulas in question three.
4. Elaborate- Students will use their knowledge of single bonds to predict the definitions for double and
triple bonds.
Summary: Covalent bonds are bonds made between two nonmetals in which electrons are shared. If two electrons are
shared, there is a single bond. If four electrons are shared, there is a double bond. If six electrons are shared, there is a
triple bond.
Day 7: Covalent Drawing with Double and Triple Bonds
Objectives (SWBAT):
Physical Science 23- Model covalent bond formation using Lewis Dot diagrams (ball-and-stick modelling)
Physical Science 5- Write formulas for covalent bonds from drawings
Physical Science 9- Identify the number of bonds an atom can form given the number of valence electrons
Physical Science 13- Draw Lewis Dot diagrams (ball-and-stick models) for single, double, and triple bonds, as well as for
diatomic molecules
Evaluated by:
Covalent Bonding Practice
Class structure:
Do Now: Draw the compounds SF2. What type of bond is present?
1. Engage- Students will share their answers for the definitions of double and triple bonds then the teacher
will complete the top four problems on question 7 of day 6’s worksheet with the class. (Teacher will
point out the diatomic structure and define this term)
2. Explore- Students will complete the drawings for the remaining problems on the worksheet from day 6.
3. Explain- Students will pair/share the structures they drew to check their work as a class.
4. Elaborate- Students will complete the covalent bonding practice sheet and identify any double or triple
bonds present by name. Students will also draw a cloud around the formulas for any diatomic
structures drawn.
Summary: Atoms of the same nonmetal can bind together to form one molecule called a diatomic (2 atom) molecule.
Only hydrogen, nitrogen, oxygen, fluorine, chlorine, bromine, and iodine do this.
Day 8: Breaking the Octet Rule and Polyatomic Ion Drawing
Objectives (SWBAT):
Physical Science 9- Identify the number of bonds an atom can form given the number of valence electrons
Physical Science 13- Draw Lewis Dot diagrams (ball-and-stick models) for polyatomic ions
Evaluated by:
Breaking the Octet Rule/Polyatomic Ion Drawing Worksheet
Class structure:
Do Now: Name two elements that would form a covalent bond with each other.
1. Engage- The class will review the octet rule then the teacher will show how covalent compounds can
break this rule due to the more complete quantum mechanical model with compound #1 (BF3).
2. Explore- Students will draw the Lewis structures for the covalent compounds that break the octet rule
(questions 3-5) at the bottom of the page to determine which element in the compound breaks the
octet rule.
3. Explain- Students will use their drawings and the three example drawings to determine the pattern to
determining which element in a compound breaks the octet rule then check their work with questions 7
and 8.
4. Elaborate- With the second half of class, the teacher will review the meaning of a positive or negative
charge then use this to explain how to draw polyatomic ions. Students will complete the worksheet to
practice this more complex drawing then combine all the information learned on day 8 in the final two
formulas.
Summary: The central atom in a covalent compound can sometimes break the octet rule and have more or less than 8
valence electrons. This can even happen in polyatomic ions. Polyatomic ions are covalent molecules with missing
electrons (resulting in a positive charge) or extra electrons (resulting in a negative charge) that allow them to be more
stable.
Day 9: Review for Lewis Drawing Test
Objectives (SWBAT):
Physical Science 5, 9, 13, 14, 16, and 23 and Inquiry 3 and 6- demonstrate at least 75% proficiency over the material of
the past two weeks
Evaluated by:
Test Review
Class structure:
Do Now: Organize your binder for tomorrow’s check.
1. Engage- Students will review the vocabulary for this unit then use a blank sheet of paper to create three
categories- ionic, metallic, and covalent.
2. Explore- Students will create a foldable of the topics for this unit. For each type of bond they will
include a picture of the structure, a list of the properties, and a short explanation of the connection
between the two.
3. Explain- The teacher will then review drawing and formula writing by going over the answers to the
completed test review.
4. Elaborate- Students will continue to study the material at home for day 10’s quiz.
Summary: For ionic compounds, electrons are transferred in the drawing and the formula can be easily written be
crisscrossing the charges of the ions down into subscripts. For covalent compounds, electrons are shared in the drawing
(indicated by 1 stick per two electrons) and the formula can only be written by using the picture. The more metallic
element is written first with its subscript then the less metallic with its subscript.
Day 10: Lewis Structures
Objectives (SWBAT):
Physical Science 5, 9, 13, 14, 16, and 23 and Inquiry 3 and 6- demonstrate at least 75% proficiency over the material of
the past two weeks
Evaluated by:
Test- Lewis Structures
Class structure:
Do Now: Take out a calculator and something to write with, open your binder to the table of contents and place
it on the back bench, move your bags to the A/C, and clear your calculator RAM
TEST
Summary: Lewis structures are a tool we will build on in the next unit (forces). The structure of a compound is
important because it determines the compound’s properties.
GLE
Objective
Day(s) Addressed
Inquiry 3
Plan and record step-by-step procedures for a valid investigation, select equipment
and materials, and identify variables and controls
Use technology when appropriate to enhance laboratory investigations and
presentations of findings
Write and name formulas for ionic and covalent compounds
3, 4
Physical
Science 9
Draw accurate valence electron configurations and Lewis dot diagrams for selected
molecules, ionic and covalent compounds, and chemical equations
1, 6, 7, 8
Physical
Science 13
Identify the number of bonds an atom can form given the number of valence
electrons
6, 7, 8
Physical
Science 14
Identify unknowns as elements, compounds, or mixtures based on physical
properties
4, 5
Physical
Science 16
Predict the stable ion(s) an element is likely to form when it reacts with other
specified elements
2
Physical
Science 23
Model chemical bond formation by using Lewis dot diagrams for ionic, polar, and
nonpolar compounds
1, 2, 6, 7
Inquiry 6
Physical
Science 5
Vocabulary
Ionic Compound
Double Bond
Polyatomic Ion
Covalent Compound
Triple Bond
Diatomic
Single Bond
Octet Rule
3, 4
1, 6, 7
Assessment Design
Basic: 6 Questions
Standard: 12 Questions
Expanded: 6 Questions
Essential Skills and Learning Objectives
Type of
Question
(MC, CR, P)
Basic
(Remember &
Understand)
Standard
(Apply &
Analyze)
Expanded
(Evaluate &
Create)
Write the formulas for ionic and covalent compounds given
two elements or ions
MC/CR
1 MC
2 CR
1 CR
Draw accurate Lewis dot diagrams for selected molecules
and use these to model chemical bond formation for ionic
and covalent compounds
MC/CR/P
1 MC
4 CR
3 CR
Identify the number and type of bonds an atom can form
given the number of valence electrons
MC/CR
1 MC
2 CR
1 CR
Identify unknowns as elements, ionic compounds, metallic
alloys, or covalent compounds based on physical properties
MC/CR/P
1 MC
2 MC
1 CR
Predict the stable ion(s) an element is likely to form when it
reacts with other specified elements
MC/CR/P
1 MC
1 CR
Explain the octet rule and when/how it can be broken
MC/CR
1 MC
1 CR