Lesson Plan | Traditional Methodology | Periodic Table: Introduction

Objectives

Duration: (10 - 15 minutes)

The purpose of this stage is to provide a clear and structured overview of the main objectives of the lesson, ensuring that students understand what is expected of them regarding the periodic table. This helps guide both the teacher and the students by establishing a clear and specific focus for the lesson.

Main Objectives

1. Understand the basic structure of the periodic table.

2. Identify the organization of elements in the periodic table, including metals and nonmetals.

3. Recognize the main families of the periodic table, such as the halogens.

Introduction

Duration: (10 - 15 minutes)

The purpose of this stage is to capture students' attention and provide a contextual foundation about the importance of the periodic table. By presenting the history and curiosities related to the periodic table, the teacher can create a more engaging learning environment and show the topic's relevance to everyday life and science. This helps prepare students for deeper understanding in the subsequent stages of the lesson.

Context

Start the class by explaining that the periodic table is a fundamental tool in chemistry as it organizes all known elements in a way that their properties can be easily identified and compared. Explain that Dmitri Mendeleev, a Russian scientist, was one of the first to create a version of the periodic table in 1869, organizing the elements according to their chemical properties and atomic masses. Today, the periodic table is organized by atomic number, which is the number of protons in an atom's nucleus. The table is divided into periods (horizontal rows) and groups or families (vertical columns), and understanding this organization is crucial for grasping many concepts in chemistry.

Curiosities

Did you know that the periodic table can help us understand why sodium (Na) and chlorine (Cl) together form table salt (NaCl)? Or that the gold (Au) we use in jewelry is found in the same periodic table as hydrogen (H), the lightest and most abundant element in the universe? These interactions and combinations between elements are possible because of how the periodic table organizes and shows us the properties of each element.

Development

Duration: (45 - 55 minutes)

The purpose of this stage is to provide a detailed understanding of the organization and classification of elements in the periodic table. By addressing specific and essential topics and providing practical questions, students can internalize and apply the discussed concepts. This detailed approach prepares students to recognize patterns in the periodic table and understand the importance of element classification in chemistry.

Covered Topics

1. Structure of the Periodic Table: Explain that the periodic table is organized into horizontal rows called periods and vertical columns called groups or families. Each element is positioned according to its atomic number, which is the number of protons in its nucleus. 2. Metals, Nonmetals, and Metalloids: Detail the classification of elements into metals, nonmetals, and metalloids. Metals are good conductors of electricity and heat, usually solid at room temperature (except for mercury) and have a metallic luster. Nonmetals have properties opposite to metals, such as being poor conductors of electricity and heat. Metalloids have intermediate properties between metals and nonmetals. 3. Main Families: Identify and explain the main families of the periodic table, such as the halogens (group 17), noble gases (group 18), alkali metals (group 1), and alkaline earth metals (group 2). Discuss the common characteristics of each family, such as reactivity and physical states.

Classroom Questions

1. What is the difference between a period and a group in the periodic table? 2. Why are metals good conductors of electricity, while nonmetals are not? 3. Identify three elements belonging to the halogen family and describe one common property they share.

Questions Discussion

Duration: (20 - 25 minutes)

The purpose of this stage is to ensure that students consolidate the knowledge acquired during the lesson, clarifying any doubts and reinforcing the main concepts. Through the discussion of responses and continuous engagement, students have the opportunity to apply what they have learned, promote critical thinking, and connect the content to the broader context of science and everyday life.

Discussion

•  What is the difference between a period and a group in the periodic table?

• A period is a horizontal row in the periodic table. Elements in the same period have the same number of electron shells. A group or family is a vertical column. Elements in the same group have similar chemical properties due to the same number of electrons in the valence shell.

•  Why are metals good conductors of electricity, while nonmetals are not?

• Metals have free electrons in their valence shell, which allows them to move easily and conduct electricity. Nonmetals, on the other hand, have electrons more tightly bound to the atomic nuclei, preventing the conduction of electricity.

•  Identify three elements belonging to the halogen family and describe one common property they have.

• Three elements from the halogen family are Fluorine (F), Chlorine (Cl), and Bromine (Br). A common property among these elements is their high reactivity, especially with metals, forming salts.

Student Engagement

1. ❓ Ask the students: How does the organization of the periodic table facilitate the prediction of element properties? 2. ❓ Suggest that students discuss: How can the reactivity of halogens be observed in everyday life? 3. ❓ Ask students to reflect: Why is it important for scientists to understand the classification of elements as metals, nonmetals, and metalloids?

Conclusion

Duration: (10 - 15 minutes)

The purpose of this stage is to consolidate students' learning by recapping the main points addressed during the lesson and reinforcing the connection between theory and practice. This helps solidify knowledge and understand the relevance of the subject, preparing students for future lessons and applications of the content.

Summary

• The periodic table is a fundamental tool in chemistry that organizes all known elements in a way that their properties can be easily identified and compared.
• Dmitri Mendeleev was one of the first to create the periodic table in 1869, organizing elements according to their chemical properties and atomic masses.
• Today, the periodic table is organized by atomic number, which is the number of protons in an atom's nucleus.
• The table is divided into periods (horizontal rows) and groups or families (vertical columns).
• Elements can be classified into metals, nonmetals, and metalloids, each with distinct properties.
• The main families of the periodic table include the halogens (group 17), noble gases (group 18), alkali metals (group 1), and alkaline earth metals (group 2).

The lesson connected the theory of the periodic table with practice by explaining how the organization of elements can predict their properties and chemical behaviors. Practical examples, such as the formation of table salt (NaCl) and the reactivity of halogens, were used to illustrate these connections in a tangible and applicable manner to students' everyday lives.

The importance of the theme presented is highlighted by its practical relevance in daily life. The periodic table not only helps us understand the properties of materials we use daily but is also crucial for scientific and technological advancements. Curiosities such as the formation of common compounds and the reactivity of elements demonstrate the direct application of this knowledge in everyday life and in industry.