Contextualization

Chemistry is the science that studies the composition, structure, and properties of matter as well as the changes it can undergo in chemical reactions. It is a fundamental science that helps explain the world around us. Within it, a particularly important topic is chemical formulas.

Chemical formulas are encoded representations that describe the composition of compounds and molecules, in other words, they are the 'name' of substances in the language of chemistry. They are a concise way to express information about the atoms that make up a particular chemical substance. A chemical formula indicates the types of atoms present, as well as the proportion of these atoms. Therefore, every chemical formula carries a series of information about the substance it represents.

There are different types of chemical formulas: molecular formulas, which tell us which atoms are present in the molecule and in what quantity; structural formulas, which reveal the arrangement of atoms in the molecule, and empirical formulas, which give us the proportion of atoms in a molecule. Each of them is useful in different contexts and for different purposes.

Chemical formulas are one of the most fundamental parts of chemistry, as they help us understand the exact composition of substances. Chemical substances are all around us, from the food we eat, the drinks we consume, the medicines we take, the fuels we use in our cars, and even the air we breathe. In almost every industry, from pharmaceuticals to food, textiles, and energy, chemical formulas are essential for the manufacturing of products.

For example, the formula for water, H2O, tells us that water is composed of two hydrogen atoms and one oxygen atom. This basic information is the starting point for understanding the properties of water, such as its ability to dissolve other substances, its melting and boiling points, among others.

Therefore, mastering the understanding of chemical formulas is the first step in understanding the chemical world that surrounds us - a relevant topic in daily life and in various professions.

Practical Activity

Activity Title

"Unraveling Chemical Formulas: A Playful and Collaborative Approach"

Project Objective

Understanding the representation of chemical formulas at the molecular, structural, and empirical levels through the construction of 3D models, preparation of a presentation, and writing of a technical report.

Detailed Project Description

The project will be carried out in groups of 3 to 5 students, lasting approximately one month. It consists of choosing and representing three chemical compounds from different categories (for example, an acid, a base, and a salt). Each group will build 3D models of the chosen compounds, create a didactic presentation explaining their chemical formulas, and finally write a technical report that reports their experience in the project and the lessons learned.

Required Materials

• Modeling clay in various colors
• Toothpicks
• Presentation software (PowerPoint, Google Slides, Prezi, etc.)
• Research material (chemistry books, scientific articles, reliable websites, etc.)

Detailed Step-by-Step for Activity Execution

1. Choosing the Compounds: The group must choose three chemical compounds that will be the focus of the project. These compounds should be from different categories so that students can explore the variation in their structures and formulas.

2. Research and Formulation of Formulas: Students should research the chemical formulas of the chosen compounds, noting their molecular, empirical, and structural formulas.

3. Construction of 3D Models: Using modeling clay and toothpicks, the group will build 3D models for each of the compounds, accurately representing the quantity and arrangement of atoms.

4. Preparation of the Presentation: The group should create a presentation explaining their choices of compounds, the chemical formulas, and the created 3D models. The presentation should be didactic and visually appealing.

5. Writing the Report: Finally, the group should write a technical report, following the format of Introduction, Development, Conclusions, and Bibliography. In this report, students will explain their choice of compounds, describe the research steps, formulation of formulas, and construction of 3D models, and discuss what they learned in practice about chemical formulas.

Project Deliverables

Report: The report should be written clearly and objectively, containing all four suggested topics: Introduction, Development, Conclusions, and Bibliography. The introduction should contextualize the theme and the project's objective. In the development, students should explain the theory behind the chosen compounds, the formulation of chemical formulas, and the process of building 3D models. It is essential that they present and discuss the results obtained. In the conclusion, students should summarize the main points, discuss the learnings, and draw conclusions about the project. Finally, a complete bibliography of the sources used should be included.

Presentation: The presentation should be clear, didactic, and visually appealing. It should explain the chosen compounds, their chemical formulas, and how the 3D models represent these formulas.

3D Models: The 3D models should be made with attention to detail and accuracy, faithfully representing the atoms and bonds in the chosen compounds. They will be one of the main evaluation items of the group's understanding of chemical formulas.

At the end of the project, it is expected that students have acquired technical skills in understanding chemical formulas, as well as socio-emotional skills such as time management, communication, problem-solving, creative thinking, and proactivity.