MYP Chemistry Unit
Atomic Theory and Structure
Atomic theory and structure unit
overview
This unit involves the following chemistry concepts.
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Atomic theory
Organization of the periodic table
Atomic structure
Bohr models and Lewis dot diagrams
Isotopes and ions
Quantum mechanical model
Electron configuration and orbital-filling diagrams
Famous scientists who contributed to atomic theory
Unit rationale
This unit is designed to investigate the development of atomic theory throughout time. A main
focus is atomic structure and the quantum model. Notes are provided for electron configuration
and orbital filling in case those concepts are a part of your curriculum. If not, adjust the unit as
appropriate.
Suggested lesson plan
Lesson 1: The nature of science discussion activity
Objective: The student will explore the philosophical and theoretical nature of science and answer
questions based on a conversation in The God Particle by Leon Lederman.
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Essential knowledge
Plan
1. Distribute 1.1 The God Particle Discussion
Constant re-evaluation in the light of new
Questions before students begin to read.
data is essential to ensure scientific
2.
1.2 The God Particle extract. Allow 15
knowledge remains current. In this fashion,
minutes for students to read and find
all forms of scientific knowledge remain
answers.
flexible and may be revised as new data
3. Conduct discussion activity using one of
and new ways of looking at existing data
the formats from 1.3 God Particle
become available.
Discussion Instructions for Teachers.
4. Reflection activity for homework: How do
the questions we ask impact on the
answers we receive?
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MYP Chemistry Unit
Atomic Theory and Structure
Lesson 2: The periodic table
Objective: The student will discover that the periodic table is ordered by groups and periods,
along with family names, and discuss those who contributed to this design.
Essential knowledge
• Horizontal rows called periods have
predictable properties based on an
increasing number of electrons in the
outer orbitals.
• Vertical columns called groups have
similar properties because of their
similar valence electron configurations.
• The names of groups and periods on the
periodic chart are alkali metals, alkaline
earth metals, transition metals,
halogens, noble gases and metalloids.
• Periods and groups are named by
numbering columns and rows.
Plan
1. Distribute 2.1 Periodic Table (make this
two-sided). The first side of the periodic
table will be used for colouring family
names. Students should also label and
number groups and periods.
Distribute 2.2 Atomic Theory & Structure
Guided Notes. (Notes will be used for the
duration of the unit.
2. Complete section I along with
2.3 Organization of the Periodic Table
Presentation.
3. Homework: Students will colour-code
their periodic tables by family names on
one side only.
Lesson 3: Atomic theory
Objective: The student will discover how the model of the atom has changed over time. The
student will also memorize the key scientists who contributed to atomic theory, along with their
experiments and discoveries. The student will evaluate the results of each scientist’s experiment.
Essential knowledge
• Discoveries and insights related to the
atom’s structure have changed the
model of the atom over time.
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• The periodic table is arranged in order
of increasing atomic numbers.
• Major insights regarding the atomic
model of the atom and principal
scientists include:
- particles—Democritus
- first atomic theory of matter—John
Dalton
- discovery of the electron—JJ
Thompson
- discovery of the nucleus—Ernest
Rutherford
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4.
Plan
Distribute 3.1 Element Groups Worksheet
as a warm-up. Review the answers.
Teach Section II of 2.2 Atomic Theory &
Structure Notes with 3.2 Atomic Theory
Presentation Slides 1–10. Videos are
linked and/or embedded.
Headline reflection: All students must
write a headline that summarizes the
lesson and how it applies to the unit
question.
Homework: Distribute 3.3 Atomic Theory
& Structure Homework Packet. Students
must complete section A.
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MYP Chemistry Unit
Atomic Theory and Structure
- discovery of charge of electron—
Robert Millikan
- planetary model of atom—Niels Bohr
- periodic table by atomic mass—
Demitry Mendeleev
- periodic table by atomic number—
Henry Moseley
- quantum nature of energy—Max
Planck
- uncertainty principle—Werner
Heisenberg
- wave theory—Louis de Broglie.
Lesson 4: Atomic structure and symbols
Objective: The student will discover the subatomic particles of the atom and how each of those
particles affects the identity of the element. Key terms include the following: atom, element,
proton, neutron, electron, atomic number, atomic mass, mass number, valence electron, atomic
mass unit.
Essential knowledge
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The atomic number of an element is the
same as the number of protons.
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In a neutral atom, the number of
electrons is the same as the number of
protons.
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All atoms of an element have the same
number of protons.
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The atomic mass for each element is
the weighted average of that element’s
naturally occurring isotopes.
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Electrons have little mass and a
negative (–) charge. They are located in
electron clouds or probability clouds
outside the nucleus.
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Protons have a positive (+) charge.
Neutrons have no charge. Protons and
neutrons are located in the nucleus of the
atom and comprise most of its mass.
Plan
1. Distribute 4.1 Atomic Theory Timeline
Worksheet as a warm-up. Review.
2. Discuss 2.2 Atomic Theory & Structure
Guided Notes Section III using 4.2 Atomic
Structure Presentation for help.
3. Complete 4.3 Atomic Structure
Investigation.
5. Homework: Distribute 3.3 Atomic Theory
& Structure Homework Packet. Students
must complete Section B.
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MYP Chemistry Unit
Atomic Theory and Structure
Lesson 5: Modelling for Bohr and Lewis
Objective: The student will create Bohr models and Lewis dot structures for elements.
Essential knowledge
• Draw Bohr models and
Lewis dot diagrams for
atoms.
Plan
1. Distribute 5.1 Atomic Structure Practice as a warm-up.
http://www.corvallis.k12.mt.us/high/staff/brockh/Chemistry/Ch5/CRM050
6.pdf
2. Give instruction on Bohr models and Lewis structures using 5.2
Teacher Guide for Bohr Models.
3. Complete 5.3 Bohr Model & Lewis Structure Worksheet as class
work.
4. Homework: 3.3 Atomic Theory & Structure Homework Packet,
sections C and D (only the questions that apply).
Lesson 6: Changing an atom’s structure
Objective: The student will discover what happens when the number of protons, neutrons, or
electrons is changed in an atom. The student will calculate average atomic mass using
abundance and mass numbers.
Essential knowledge
• The atomic mass for each element is
the weighted average of that element’s
naturally occurring isotopes.
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• An isotope is an atom that has the
same number of protons as another
atom of the same element but has a
different number of neutrons. Some
isotopes are radioactive; many are not.
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• Atoms can gain, lose or share electrons
within the outer energy level.
• Loss of electrons from neutral atoms
results in the formation of an ion with a
positive charge (cation).
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Plan
Distribute and assign 6.1 Cloze Reading
Passage.
Complete 2.2 Atomic Theory & Structure
Guided Notes section III.
Distribute 6.2 Solving and Naming Isotopes
Worksheet.
Distribute 6.3 Another Isotope Worksheet
and complete “Average Atomic Mass
Problems” section. Leave part A blank for
lesson in class.
Homework: Complete all questions up to
and including section D of 3.3 Atomic
Theory & Structure Homework Packet. Also
complete 6.4 Practice with Ions & Isotopes.
• Gain of electrons by a neutral atom
results in the formation of an ion with a
negative charge (anion).
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MYP Chemistry Unit
Atomic Theory and Structure
Lesson 7: The quantum model part 1—Electron configuration1
Objective: The student will learn how elements fit into shells, subshells, and orbitals on the
periodic table. The student will write electron configurations in both longhand and shorthand. The
student will discover contributions by Planck, Heisenberg and de Broglie.
Essential knowledge
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Discoveries and insights related to the
atom’s structure have changed the model
of the atom over time.
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The modern atomic theory model is
called the quantum mechanical model.
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Vertical columns called “groups” have
similar properties because of their similar
valence electron configurations.
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Electron configuration is the
arrangement of electrons around the
nucleus of an atom based on their energy
level.
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It is possible to use an element’s
electron configuration to determine the
number of valence electrons and possible
oxidation numbers.
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Plan
Require students to complete part A of 6.3
Isotopes Worksheet.
Show 6.1 Quantum Mechanics Video to
introduce the topic.
Answer 2.2 Atomic Theory & Structure
Guided Notes sections V and VIa.
Distribute/teach from 7.2 Learning
Electron Configuration Presentation.
Students should work alongside the
presentation. Another presentation is
offered to teach students how to actually
write electron configurations (7.3 Writing
Electron Configurations). Use this to assist
or teach it without this aid.
Homework: Complete section D of 3.3
Atomic Theory & Structure Homework
Packet and 7.4 Yet Another Atomic
Structure Worksheet.
Lesson 8: The quantum model part 2—Orbital-filling diagrams
Objective: The student will create orbital-filling diagrams showing orbitals and correct filling of
electrons using the following rules: Aufbau, Pauli’s exclusion principle and Hund’s rule.
Essential knowledge
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Electrons are added one at a time to
the lowest energy levels first (Aufbau
principle).
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An orbital can hold a maximum of two
electrons (Pauli exclusion principle).
Plan
1. Review homework from lesson 7 as a
warm-up.
2. Show 8.1 Quantum Mechanics Video 2 to
introduce orbital filling.
3. Discuss 2.2 Atomic Theory & Structure
Guided Notes section VIb.
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I have recently discovered that it is just as easy to teach orbital filling first, then electron configuration. If
your students are visual learners, this method may work better. Also, they can be taught together in the
same class time frame, using this method. I provided students with a blank periodic table, several sticky
notes, and four different colors to outline their blocks. The students used sticky notes for important
points like the number of orbitals, number of electrons in each subshell, and key rules.
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MYP Chemistry Unit
Atomic Theory and Structure
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Electrons occupy equal-energy orbitals
so that a maximum number of unpaired
electrons results (Hund’s rule).
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Energy levels are designated 1–7.
Orbitals are designated s, p, d, and f
according to their shapes.
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Orbitals s, p, d and f relate to the
regions of the periodic table.
4. Teach orbital filling, using 8.2 OrbitalFilling Diagrams Presentation to help if
you wish. Suggestion: Use the same
problems you just reviewed from
homework as classwork.
5. Thought-provoker activity: Show 8.3
Double-slit Experiment Video. Allow
students to ask questions and lead
discussion. You may have to show it twice
for students to grasp what’s actually taking
place.
6. Homework: Complete 3.3 Atomic Theory &
Structure Homework Packet. If necessary,
discuss and distribute flame test lab
instructions.
Lesson 9: The fingerprint of atoms and flame test lab
Objective: The student will discover the chemical properties of elements through color changes of
light. The student will perform a flame test lab.
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Essential knowledge
The electromagnetic spectrum is the
continuous range of light radiation.
An atomic absorption spectrum shows the
frequencies at which atoms absorb energy.
An atomic emission spectrum is the
opposite of the absorption spectrum, and
shows the frequency at which energy is
released. The atomic emission spectrum of
an element is like a fingerprint, meaning it
is unique to that element.
Plan
1. Distribute 9.1 Quantum Model Warm-Up.
2. Conduct 9.2 Flame Test Lab.
Lesson 10: Objective test
This test may serve as a pre-test for the actual assessment test. Students should receive immediate
feedback.
Lesson 11: Test assessment
.Isotopes Worksheet from Loundoun County Schools
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