Lesson 2: Oxidation Numbers & Polyatomic Ions

Why do elements have different oxidation states in compounds?
How do polyatomic ions maintain their charge in chemical reactions?
What patterns exist in oxidation numbers across the periodic table?
How are oxidation numbers used in real-world applications (e.g., batteries, rusting)?

Oxidation number (oxidation state)
Rules for assigning oxidation numbers
Polyatomic ion
Oxyanion
Parentheses in chemical formulas
Nomenclature of polyatomic ionic compounds

HS-PS1-1 Use the periodic table as a model to predict the relative properties of elements based on the patterns of electrons in the outermost energy level of atoms.

These standardized tests may include questions that assess the understanding of oxidation numbers and polyatomic ions. Students may be asked to:
Determine the oxidation number of an atom in a compound or ion.
Identify common polyatomic ions and their charges.
Write the formulas or names of ionic compounds containing polyatomic ions.

Day 1: Oxidation Numbers
Description: This lesson introduces the concept of oxidation numbers as a way to track electron distribution in chemical species. Students will learn and apply the rules for assigning oxidation numbers.
Purpose: To provide students with a tool for understanding redox reactions and for predicting the formulas of compounds.
DOK Level: 2 (Understand), 3 (Apply)

Day 2: Polyatomic Ions
Description: This lesson introduces polyatomic ions, which are groups of covalently bonded atoms that carry a charge. Students will learn to identify common polyatomic ions and determine their charges and formulas.
Purpose: To expand students' knowledge of ions beyond monatomic ions and prepare them for naming and writing formulas for more complex ionic compounds.
DOK Level: 2 (Understand)

Day 3: Nomenclature of Polyatomic Ionic Compounds
Description: This lesson focuses on applying nomenclature rules to name and write formulas for ionic compounds that contain polyatomic ions.
Purpose: To develop students' ability to communicate effectively in the language of chemistry when dealing with compounds containing polyatomic ions.
DOK Level: 3 (Apply)

Discuss the historical use of oxidation processes like fermentation in food production and beverages in different cultures.
Connect the use of fertilizers containing polyatomic ions to agricultural practices and food security in various regions of the world.

Day 1:
Students may confuse oxidation numbers with ionic charges.
Students may struggle with applying the rules for assigning oxidation numbers, especially in complex compounds.

Day 2:
Students may not understand that polyatomic ions are groups of atoms bonded together that act as a single unit with a charge.
Students may have difficulty memorizing the formulas and charges of common polyatomic ions.

Day 3:
Students may forget to use parentheses when writing formulas for compounds containing multiple polyatomic ions.
Students may make errors in naming compounds due to incorrect identification of the polyatomic ions.

Support:
Provide a list of common polyatomic ions with their formulas and charges.
Use color-coding or other visual aids to help students distinguish between monatomic and polyatomic ions.
Provide step-by-step guidance for assigning oxidation numbers and writing chemical formulas.
Offer extra practice with simpler examples before moving on to more complex ones.

Challenge:
Have students research less common polyatomic ions and their applications.
Introduce the concept of nomenclature for hydrates.
Explore the use of oxidation numbers in balancing redox equations.

Formative:

Class discussions and questioning.

Worksheet practice.

Whiteboard activities.

Observation of student participation in activities.

Summative:

End-of-lesson quizzes.

Periodic tables

Textbook

Whiteboard or projector

Computer with internet access for simulations and videos

Charts or flashcards of common polyatomic ions

Worksheets and practice problems

'4'5-3.2-Oxidation#&Nomenclature Combo (Print) (https://docs.google.com/document/d/1EjSoUY9PBTu6o_TgwvpN8V_HyWZd92raDDQFj1mf2c0/edit?usp=sharing)

3.2-Rules for Assigning Oxidation State/# and Common Polyatomic Ions(https://docs.google.com/document/d/1SZs5f-XD6Kse-c-jXXWJpok1Aw3YWAopEjkGWZfz6n0/edit?usp=sharing)