Topic: The structure of the atom and the location of the element in the periodic table

Target group

Elementary school student (grades 7. and 8.)

Core curriculum

Elementary school. Chemistry.

II. Internal structure of the matter. Student:

7) explains the relation between the similarity of the properties of elements belonging to the same group in the periodic table and a gradual change in the properties of elements located in the same period (metals – non‑metals) and the structure of atoms.

General aim of education

The student discusses the structure of the periodic table.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to determine the number of valence electrons in the atoms of the elements lying in the groups: 1., 2. and 13.–18.;

• to determine the number of coatings in atoms of elements based on the period number;

• that elements belonging to one group have similar properties, and elements from the same period do not show characteristic similarities.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers.

Lesson plan overview

Introduction

1. The teacher hands out Methodology Guide or green, yellow and red sheets of paper to the students to be used during the work based on a traffic light technique. He presents the aims of the lesson in the student's language on a multimedia presentation and discusses the criteria of success (aims of the lesson and success criteria can be send to students via e‑mail or posted on Facebook, so that students will be able to manage their portfolio).

2. The teacher together with the students determines the topic – based on the previously presented lesson aims – and then writes it on the interactive whiteboard/blackboard. Students write the topic in the notebook.

3. Health and safety – before starting the experiments, students familiarise themselves with the safety data sheets of the substances that will be used during the lesson. The teacher points out the need to be careful when working with them.

Realization

1. The teacher asks students to tell the periodical law with interpretation based on the periodic table of the elements.

2. The teacher asks pupils to indicate on the periodic table of elements the sets of elements whose atoms have the same number of valence electrons. He asks the students the question: „Can one find the regularity between the number of valence electrons and the location of the element in the periodic table?” Eager students answers; discussion is underway. The teacher adds missing information about the atom's structure based on the group to which it belongs.

3. The teacher asks students to - when working with the periodic table of elements - indicate the sets of elements whose atoms have the same number of electron shells. Then he asks the students the question: „Is it possible to find a relation between the number of electron shells and the position of the element in the periodic table?”. After a short discussion, one of the students summarizes the information. If the student did not include this in his speech, the teacher indicated that based on the record of the electronic configuration, it is possible to determine the number of electron shells from which the atom is built.

4. The teacher sums up the students' previous inquiries: there is a connection between the structure of the atom and the location of the element in the periodic table; the number of the period informs about how many electron shells the atom of the element consists of, and the numbers of groups 1, 2 and 13‑18. help determine the number of valence electrons. The lecturer asks students to write electron configurations of atoms for the indicated elements.

5. The lecturer announces the experience of „Lithium reactions with water”. Instructs students to formulate a research question and hypothesis in the form in an abstract. After conducting the experiment, the students write observations and on their basis they formulate conclusions which they write in an abstract.

6. At the end of the lesson, the teacher asks students to do interactive exercises - individual work.

Summary

1. The teacher asks the students questions:

   • What did you find important and interesting in class?

   • What was easy and what was difficult?

   • How can you use the knowledge and skills you have gained today?

   Willing/selected students summarize the lesson.

Homework

1. Listen to the abstract recording at home. Pay attention to pronunciation, accent and intonation. Learn to pronounce the words learned during the lesson.

2. Make at home a note from the lesson using the sketchnoting method.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

The structure of the atom and the location of the element in the periodic table

Periodic table next to the necessary atomic numbers and symbols of elements can also contain other information.

After careful analysis of the data contained in the periodic table of elements, it can be noticed that within some groups the elements have the same number of electrons on the last shell. This observation concerns groups: 1, 2, 4, 13, 14, 15, 16, 17 and partly 18. In groups: 3 and 5‑12 the number of these electrons in atoms of elements varies.

On the table of elements taking into indicating electron configurations, it is clearly visible that the elements whose atoms are made of the same number of shells are in the same period, in addition the number of these shells is equal to the number specifying the period number. This observation allows us to draw a general conclusion about the structure of atoms of elements, namely that the number of shells in the atoms of the element equals the number of the period in which the element is located.

There is a connection between the structure of the atom and the location of an element in the periodic table. Number of the period informs how many electric shells are consisted in the atom of the element and the group numbers 1, 2 and 13–18 help to determine the number of valence electrons.

Despite the fact that elements belonging to one group have similar properties, elements belonging to one period do not show such similarities. In periods there is a change in the character of elements – from active metals (1st and 2nd group) through active non‑metals to chemically passive noble gases.

• Period number to which given element belongs is equal to the number of electron shells in its atoms.

• Number of valence electrons in atoms of elements belonging to group 1 and 2 is equal to the group number.

• Number of valence electrons in atoms of elements belonging to groups 13–18 are obtained by subtracting 10 from the group number.

• Elements belonging to the same group show similar properties.

• Elements in the same period do not have similar properties.

Structure of the atom, periodic table, valence electrons, location of the element