Title: Simple and complex substances

Supplementary material for use in lessons in the group of natural sciences (nature, biology, chemistry, geography, physics), additional classes, science clubs. It can serve as a resource for expanding knowledge, preparing students for science competitions.

Lesson plan elaborated by: Zyta Sendecka

Target Group

Student of the seventh grade of primary school.

Core Curriculum

7th grade of primary school – chemistry

I. Substances and their properties. Student:

1. describes the properties of substances that are the main ingredients of everyday products, e.g. table salt, sugar, flour, water, coal, aluminum, copper, zinc, iron; designs and conducts experiments in which it examines selected properties of the substance;

II. Internal structure of matter. Student:

1. uses the term chemical element as a set of atoms with a given atomic number Z;

2. describes how the atom differs from the molecule; interprets entries, e.g. H₂, 2H, 2H₂.

The general aim of education

Students describe the composition of matter as a collection of various types of particles that make up various substances and distinguish between simple substances and complex substances.

Criteria for success

• explain how a simple substance differs from a complex substance;

• give three examples of simple substances and complex substances;

• build models of some particles.

Key competences

• Communication in the mother tongue;

• Communication in foreign languages;

• Mathematical competence and basic competences in science and technology;

• Digital competence;

• Learning to learn;

• Social and civic competences.

Methods/forms of work

Talk, work with the text, workshop method, direct observation.

Group work, individual work and work in pairs.

Teaching aids

• abstract;

• interactive or traditional board;

• tablets/computers;

• colorful Lego bricks.

Lesson phases

Introduction

1. The teacher gives the subject and the purpose of the lesson in a language that the student understands as well as the criteria for success.

Realization

1. The teacher instructs students to read the section „Simple substances” write in their notebook the definition of a simple substance.

2. The teacher displays the periodic table of elements. He asks the children to choose three names of elements and note them as examples of simple substances. Selected students read their examples.

3. Each student receives two red blocks of the same size, symbolizing the elements. The students' task is to connect the blocks together. The teacher announces that in this way they will build a model of molecule.

4. Students search for the definition of a molecule in the abstract content and write it in their notebooks.

5. The teacher gives students two bricks and two, slightly smaller, white blocks. He asks students to combine three different blocks and explains that in this way they will create a chemical model.

6. Students search in the abstract text for the definition of a complex substance and copy it to a notebook. Under the definition, they write three examples of this type of substance.

7. Students independently perform an interactive exercise.

8. The teacher introduces a movie entitled „How to build models of particles”. He asks students to write down the research question and hypothesis in the form provided in the abstract. The teacher displays the movie. Students note their observations and conclusions, and then build models of substances presented in the film, in accordance with the guidelines given in the film.

Summary

1. The teacher asks pupils to use emoticons to assess whether the new content has been given to them in a way that is understandable.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Simple and complex substances

We already know that everything around us is made of atoms: trees, rocks, and even our bodies. If the substance consists of atoms of one kind, we say that it is an element or simple substance.

We know only 94 elements existing in nature. In addition, a certain amount of elements can only be obtained in laboratories. At room temperature, only two elements are liquids (bromine and mercury), eleven are gases (eg hydrogen, oxygen, nitrogen, chlorine, helium) and the remaining – solids (eg iron, carbon, sulfur, magnesium, calcium).

Most substances in nature are made up of atoms of elements joined in groups called molecules. If a molecules consist of atoms of at least two different elements, they form a complex substance.We now know thousands of such substances, and scientists are still creating and discovering new ones. Well known examples are; water, kitchen salt, sugar and vinegar.

The particles are too small to be seen with the naked eye, but we can show their construction using models. For example, the model of the water molecule shows us that it consists of two atoms of hydrogen and one atom of oxygen.

We can determine the properties of substances by performing tests such as heating or cooling the sample. We can also check how some substances behave towards others. For example, let's examine the properties of flour, sugar and citric acid.

Elements in addition to names also have chemical symbols.They are recognized all over the world. All elements are described in a special table, which we call the periodic table. From this table you can read the names and symbols of each element. In addition to names and symbols, the periodic table of elements contains other important information. Symbols of elements are an abbreviation of their Latin names. They are created by the first letter of the name, sometimes in combination with one of the following letters.

• Everything that surrounds us is made of simple or complex substances.

• Simple substances consist of atoms of the same element.

• Complex substances are composed of atoms of various elements joined into molecules.

• In order to distinguish substances from each other, we observe and study their properties.