Project: The Atom in the Kitchen

Contextualization

Chemistry is a science that allows the manipulation of matter and is responsible for the creation of an infinity of items that we use daily, from the plastic of a pen, through medication, and even the drinking water that we drink. In this science, one of the main structures to be studied is the atoms and the bonds that they form, which are fundamental to create the substances that we see in our everyday lives.

The atoms form bonds to reach stability, and the main ones of them are the ionic bonds and covalent bonds. These bonds are different both in the way they are formed as well as in their properties and applications. When we understand the way that atoms unite to form molecules, we can predict the behavior of these molecules and the type of chemical reactions that they can undergo.

Ionic and Covalent Bonds: Key Concepts

The ionic bond is the electrostatic attraction between ions of opposite charges. It occurs when an atom donates one or more electrons to another atom. The atom that donates the electron becomes a positive ion (cation) and the atom that receives the electron becomes a negative ion (anion). The attraction between these ions of opposite charges forms the ionic bond. This bond generally occurs between a metal and a nonmetal.

On the other hand, the covalent bond is formed when two atoms share one or more pairs of electrons. This bond generally occurs between two nonmetals. There are two types of covalent bonds: the polar covalent bond and the nonpolar covalent bond. In the polar covalent bond, the electrons are shared unequally, while in the nonpolar covalent bond, the electrons are shared equally.

Importance of Ionic and Covalent Bonds

Ionic and covalent bonds are extremely important for the formation of a great variety of chemical compounds. The difference between them determines the physical and chemical properties of these compounds.

Ionic compounds, for example, have high melting and boiling points and, when dissolved in water, conduct electricity. On the other hand, covalent compounds have lower melting and boiling points and, in the majority of cases, do not conduct electricity. Thus, the identification of the type of chemical bond that forms a compound is fundamental to understanding and predicting its properties and applications.

To expand your knowledge on this topic, we recommend that you consult the following sources of reliable information:

1. Book "General Chemistry and Chemical Reactions", volumes 1 and 2, by John C. Kotz, Paul Treichel and John Townsend, available in the school library.
2. Khan Academy - Ionic and Covalent Bonds
3. YouTube - Chemical Bonds Class - Professor Paulo Valim

This project will lead you to explore the theory behind ionic and covalent bonds and to put this theory into practice, increasing the understanding of these fundamental concepts.

Practical Activity: "The Atom in the Kitchen"

Objective of the Project

The project "The Atom in the Kitchen" aims to practice the theoretical concepts of ionic and covalent bonds through a practical activity based on experiments with common materials found in everyday life, particularly in the kitchen. In addition, it seeks to develop teamwork, communication, proactivity and time management skills.

Detailed Description of the Project

The project will be carried out in groups of 3 to 5 students and will have an approximate duration of one month, with each student dedicating between five and ten hours of work to the entire project. The group will be responsible for conducting two experiments, one focused on a substance with an ionic bond and another with a covalent bond. The objective is to observe the properties of these substances and correlate them with the type of chemical bond that they have.

Necessary Materials

The necessary materials can be found at home and are the following:

1. Salt (NaCl)
2. Sugar (sucrose: C12H22O11)
3. Water (H2O)
4. Heat-resistant pans
5. Stove
6. Kitchen thermometer
7. Kitchen scale
8. Measuring cups

Detailed Step-by-Step for Carrying Out the Activity

Experiment with Salt (NaCl) - Ionic Bond

1. Weigh 10 g of salt and dissolve it in 100 ml of water in a pan on the stove, observing the time that it takes to dissolve.
2. Record the temperature at which the water with salt begins to boil.
3. When finished, let the solution cool and observe if the salt solidifies.

Experiment with Sugar (C12H22O11) - Covalent Bond

4. Repeat the process with sugar, weighing 10 g and dissolving it in 100 ml of water, also observing the time that it takes to dissolve.
5. Record the temperature at which the water with sugar begins to boil.
6. When finished, let the solution cool and observe if the sugar solidifies.

Project Deliverables and Writing of the Written Document

The students should document the entire process of the experiments carried out, from the preparation to the final observations, carefully recording all of the measurements and observations. These notes will be the basis for the final project report.

The final report, submitted in digital format, should cover the following topics:

1. Introduction: Brief explanation about ionic and covalent bonds and their relevance in the real world. In addition, the students should explicitly state the main objective of the project.

2. Development: Detail the theory of ionic and covalent bonds and the methodology used to investigate these bonds. The students should describe in detail each step of the experiments carried out, presenting the observations and results obtained.

3. Conclusions: The students should analyze the results obtained, correlating the observed properties with the type of chemical bond present. They should also reflect on what they learned, both in terms of technical and socioemotional skills.

4. Bibliography: Indication of the main references and sources of information used for the development of the project.