Topic: Atom and its structure

Target group

Elementary school student (grades 7. and 8.)

Core curriculum

Primary school. Chemistry.

I. Internal structure of matter. The student:
2) describes the composition of the atom (nucleus: protons and neutrons, electrons); based on the location of the element in the periodic table, determines the number of electron shells in the atom and the number of electrons of the outer electron shell for the elements of groups 1 and 2 and 13‑18; determines the location of the element in the periodic table (group number, period number);
3) determines the number of protons, electrons and neutrons in the atom based on the atomic number and mass; uses the Indeks górny A^AIndeks dolny Z_ZE record.

General aim of education

The student discusses the structure of the atom.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• name individual elements of the atom;

• determine the space in which electrons, protons and neutrons are located;

• use the term: nucleons, mass number, atomic number

• determine the number of protons, neutrons, and electrons based on atomic and mass numbers.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • film;

  • exposition.

• 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.

Realization

1. The teacher refers students to the abstract, e‑textbook, textbooks and the Internet. He divides them into groups, distributes sheets of paper and markers. He instructs them to develop the issue of atom properties. After the work the group leaders report the effects of the activities. The teacher summarizes the students' work, and the most important properties of the atom are written by the students in notebooks.

2. The teacher announces the animation entitled „Atom structure and its charge”. He asks pupils to pay attention to what the atom is made of during the projection. After watching the film, the students complete the form in the abstract .

3. The teacher emphasizes that in order to describe the atom one should give the number of protons (or electrons) and neutrons included in it. Next, students try to present the helium atom in various ways, using a sketchbook in the abstract (task 2). After completing the task, the students discuss and compare their drawings.

4. The lecturer discusses describing the atom - introduces the notions: atomic number (Z), mass number (A). It displays a table in the abstract on a multimedia board and discusses its contents. Then he explains how to calculate the number of neutrons in the nucleus of each element, given the number of nucleons and protons.

5. The teacher divides the class into 4 groups. Each of them assigns one element and asks students to specify the number of protons, neutrons, electrons, atomic mass and atomic number for each of them. The group that will give the correct answer wins.

6. Students carry out the interactive exercises checking the level of knowledge learned during the lesson. The teacher initiates a discussion during which the correct solutions for all the exercises performed by the students are discussed.

Summary

1. Teacher asks: If there was going to be a test on the material we have covered today, what questions do you think would you have to answer? If the students do not manage to name all the most important questions, the teacher may complement their suggestions.

2. The teacher displays the criteria for success and asks the students to assess their skills acquired during the classes.

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.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Atom and its structure

The basic elements constructing the matter are atoms. The substances that create the material world are made up of different atoms. Atoms have mass, volume and shape. Each element consists of atoms of only one kind: iron – from atoms of iron, and gold - from atoms of gold. Individual atoms of iron and gold are made up of the same particles and only their amount is different. Therefore, these differences are sufficient and these create elements with different properties.

Each atom is an electrically neutral particle (it is not charged). In its interior, negative and positive charges are balanced. It means that the number of protons and electrons in each atom is the same.

The number of neutrons does not affect the atom's affiliation to a given element.

The negative charge of the electron and the positive charge of the proton have the same absolute value (these differ only in characters). It was found out that the negative charge of the electron is an elementary negative charge. Thus, the proton has an elementary positive charge.

To describe an atom, give the number of protons (or electrons) and neutrons included in it.

Atoms can be described with two numbers: atomic and mass. Atomic number ($\text{Z}$) is the number of protons in the nucleus, whereas mass number ($\text{A}$) is the number of nucleons (the sum of protons and neutrons). These numbers are ordered and located next to the symbol of the element. On the left side of the symbol in the upper index, the mass number $\text{A}$ is located, and in the lower index - atomic number $\text{Z:}{}_{\text{Z}}{}^{\text{A}}\text{E}$.

In the description of the mass of atoms, a value called atomic mass unit or unit which is marked with the symbol u is used. Its value is 0.00000000000000000000000166 g (1.66 · 10Indeks górny -24^-24 g)

The mass of the element's atom, which is expressed by this unit, is called the atomic mass.

The atomic mass of hydrogen is about 1 u, which means that the actual mass of the hydrogen atom is equal to one unit, i.e. 0.00000000000000000000000166 g (1.66 · 10Indeks górny -24^-24 g).

The mass of subatomic particles can also be expressed in atomic mass units. It turns out that the masses of the proton and neutron are equal to about 1 u. The mass of the electron is much smaller than the mass of the proton and neutron.

• The basic element of matter is the atom.

• The atom is made of a nucleus and electrons moving around it (negatively charged particles).

• The atomic nucleus is located in the centre of the atom and consists of nucleons, which are protons (particles with a positive charge) and neutrons (uncharged particles).

• Nearly the entire mass of the atom is concentrated in the atomic nucleus.

• The number of electrons and protons in the atom is the same.

• Atoms are described by mass number ($\text{A}$) and atomic number ($\text{Z}$) – ${}_{\text{Z}}{}^{\text{A}}\text{E}$.

• The atomic number is the number of protons in the atomic nucleus.

• The mass number is the sum of the number of protons and the number of neutrons in the nucleus of the atom.

• Unit of atomic mass is unit [u], and its value is 1.66 · 10Indeks górny -24^-24 g.