Lesson Plan | Active Learning | Chemical Formulas

Assumptions: This Active Lesson Plan assumes: a 100-minute class, prior student study with both the Book and the start of Project development, and that only one activity (among the three suggested) will be chosen to be conducted during the class, as each activity is designed to take up a significant portion of the available time.

Objectives

Duration: (5 - 10 minutes)

The Objectives stage is crucial for establishing the learning goals of the lesson. By clearly defining what is expected of students, this section directs the focus of both students and the teacher to the central aspects of the study of chemical formulas. Through the specified objectives, students will be prepared to apply and consolidate prior knowledge, ensuring a deep understanding and the ability to apply these skills in practical and theoretical contexts.

Main Objectives:

1. Empower students to find the chemical formula of compounds by identifying and combining the elements that constitute them.

2. Develop the ability to differentiate and correctly interpret the different forms of representation of chemical formulas, such as the molecular formula, structural formula, and developed formula.

Side Objectives:

1. Encourage critical thinking by analyzing and comparing different compounds and their formulas.
2. Promote collaboration and communication among students during practical activities.

Introduction

Duration: (20 - 25 minutes)

The Introduction stage aims to engage students with the content that will be explored during the lesson, using problem situations that stimulate critical thinking and the practical application of previously studied concepts about chemical formulas. Additionally, by contextualizing the importance of chemical formulas through real and historical examples, the goal is to increase students' interest and relevance of the topic, facilitating the connection between theory and practice.

Problem-Based Situations

1. Imagine you are a chemist working in a laboratory and need to verify the composition of a new medication. The label on the bottle states that it contains carbon, hydrogen, and oxygen. How would you determine the chemical formula of the medication's active compound?

2. A chemistry student creates a new compound for an experiment and asks you, as the teacher, to help name and correctly represent the formula of the compound. The elements present are nitrogen, hydrogen, oxygen, and sulfur. How would you proceed?

Contextualization

Chemical formulas are the language of chemistry, allowing scientists to communicate and understand the structure of compounds. To exemplify the practical importance, imagine that a cosmetics company needs to develop a new product and must understand the exact chemical composition of the ingredients to ensure safety and effectiveness. Moreover, the history of chemistry is filled with discoveries that were made possible thanks to the understanding of formulas, such as the discovery of penicillin, which revolutionized the treatment of infections.

Development

Duration: (70 - 75 minutes)

The Development stage is designed for students to practically and interactively apply the concepts of chemical formulas they studied previously. Working in groups, they will face challenges that stimulate critical thinking, collaboration, and the direct application of knowledge in simulated and real scenarios, such as identifying unknown compounds and constructing molecular structures. This method not only consolidates learning but also promotes communication and teamwork skills.

Activity Suggestions

It is recommended to carry out only one of the suggested activities

Activity 1 - Chemical Formula: The Mystery of the Unknown Compound

> Duration: (60 - 70 minutes)

- Objective: Apply knowledge about chemical formulas in practice to identify unknown compounds, developing analytical and logical reasoning skills.

- Description: In this activity, students will be divided into groups of up to 5 people. Each group will receive a series of bottles containing solutions of different chemical compounds. The labels are all illegible, but each bottle has a tag with the elements supposedly present. Students will need to use their knowledge of chemical formulas to determine the composition of each bottle and label them correctly.

- Instructions:

• Form groups of up to 5 students.

• Distribute the bottles with the solutions and the element tags to each group.

• Ask each group to list all possible combinations of chemical formulas present in each bottle.

• Each group must justify their choices based on the valency of the elements and their atomic proportions.

• After group discussion, each bottle must be correctly labeled with the chemical formula determined by the group.

Activity 2 - Formula Builders: Creating Molecular Structures

> Duration: (60 - 70 minutes)

- Objective: Understand and apply the concepts of structural and developed formulas, promoting teamwork and the ability to explain complex concepts clearly.

- Description: Students, in groups, will receive a set of atomic models to represent different compounds. The challenge will be to reconstruct the structural and developed formula of each compound using these models, identifying bonds and atomic arrangements. Each group will present their findings and explain the reasoning behind the formation of the bonds.

- Instructions:

• Divide the class into groups of up to 5 students.

• Provide each group with a set of atomic models of different elements.

• Students should use the models to build the molecular structure of the provided compounds.

• Each group must identify the types of bonds present and describe the developed and structural structure of the compound.

• Each group will present their compound and explain the construction process and the justification for the identified bonds.

Activity 3 - The Great Formula Challenge: Speed Competition

> Duration: (60 - 70 minutes)

- Objective: Develop quick reasoning and collaboration skills, applying knowledge of chemical formulas in a playful and dynamic way.

- Description: Turn the classroom into an interactive competition. Each group of students will receive a 'rescue kit' that contains clues, puzzles, and challenges related to discovering chemical formulas. The goal is to be the first group to decipher all the formulas and save the 'lost scientist.'

- Instructions:

• Organize the room into challenge stations, each with a puzzle or challenge that leads to a chemical formula.

• Divide the class into groups of up to 5 students and assign an initial station for each group.

• Groups must solve the challenge at their station to obtain a part of a chemical formula.

• Upon completing a formula, the group must race to the next station, where a new challenge awaits.

• The first group to complete all the formulas and 'rescue' the scientist wins the competition.

Feedback

Duration: (15 - 20 minutes)

The purpose of this feedback stage is to consolidate learning, allowing students to reflect on the activities performed and articulate their understanding in a collaborative context. The group discussion helps identify gaps in knowledge and develop a deeper understanding of the topic, while also promoting communication and argumentation skills. This moment also serves for the teacher to assess students' understanding and clarify any remaining questions.

Group Discussion

To initiate the group discussion, the teacher can ask each group to share their findings and difficulties encountered during the activities. Encourage students to explain the reasoning behind the formulas they determined and how they applied theoretical concepts in practical situations. This is a crucial moment for students to articulate their understanding and receive feedback from peers and the teacher.

Key Questions

1. Which elements were the most challenging to combine to form the formulas of unknown compounds and why?

2. How did understanding the different forms of representation of chemical formulas (molecular, structural, developed) help resolve the proposed challenges?

3. Was there any moment when the group disagreed about the correct formula of a compound? How did you resolve that issue?

Conclusion

Duration: (10 - 15 minutes)

The aim of this Conclusion stage is to consolidate learning, ensuring that students have understood the essential concepts covered during the lesson and recognize their applicability. By summarizing key points and connecting theory to practice and daily life, students can see the value of what they have learned and how it applies in the real world, reinforcing motivation and interest in the study of chemistry.

Summary

In this conclusion, we summarize the importance and application of chemical formulas, highlighting the skill developed by students to find and manipulate these formulas in different contexts. We revisit the different forms of representation (molecular, structural, and developed) and how each contributes to effective understanding and communication in chemistry.

Theory Connection

Today's class was a clear link between theory and practice. Students not only reviewed the concepts of chemical formulas but also applied these concepts in practical activities that simulated real situations, such as identifying unknown compounds and constructing molecular structures. This reinforced theoretical understanding through practice, demonstrating the relevance and applicability of chemical knowledge.

Closing

Finally, it is crucial to emphasize that knowledge of chemical formulas goes beyond the classroom. The ability to interpret and create chemical formulas is essential for various professions, from medicine to engineering. Understanding and applying this knowledge not only enriches the academic experience but also prepares students for future challenges and opportunities in their careers.