Topic: Mixtures and their division

Target group

Elementary school student (grades 7. and 8.)

Core curriculum:

Primary school. Chemistry.

I. Substances and their properties. Pupil:

6) prepare mixtures and selects the method of separation of mixture components (eg filtration, distillation, separation of liquid in a separator); indicates these differences between the physical properties of the components of the mixture that enable its separation.

General aim of education

The student explains the term of the mixture and divides the mixtures.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• what a mixture is;

• to indicate examples of mixtures in the immediate vicinity;

• to divide mixtures;

• to describe the characteristics of homogeneous and heterogeneous mixtures;

• to distinguish a homogeneous mixture from a heterogeneous one;

• to explain the differences between the mixture and the chemical compound;

• to make a simple mixture.

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 introduces students to the problem of mixtures, giving examples: „Water is a substance composed of hydrogen and oxygen. Is a chemical compound. The air components are: oxygen, nitrogen, carbon dioxide, water vapor and other gases. Is air also a chemical compound or a mixture? What is the difference between a mixture and a chemical compound? „ He initiates the discussion with his questions.

2. The teacher announces a movie. He instructs his pupils to write a research question and a hypothesis in the form provided in the abstract. Then he plays the video and the students note their observations and conclusions. The teacher points the person who shares his insights and explains the reasonableness of the conclusions noted.

3. The teacher instructs students to follow the instructions 2. Students answer questions by working in pairs. After the time set by the lecturer, volunteers present the results of their work on the class forum. The teacher together with other students assess the correctness of the answers presented.

4. Students look at photos of mixtures in the photo gallery, and then carry out the experiment in accordance with the instructions contained in the abstract (experiment 1). Selected people share their observations with colleagues. The class that has been worked out together is saved in the form.

5. The participants analyze the interactive illustration and indicate other mixtures from their immediate surroundings.

6. The teacher instructs students to read the passage titled „Types of mixtures”. He chooses one student by random method and asks him to present the meaning of the terms in his words: homogeneous mixtures and heterogeneous mixtures.

7. Students, working individually or in pairs, carry out interactive exercises to check and consolidate knowledge learned during the lesson. Selected people discuss the correct solutions for interactive exercises. The teacher completes or straightens the statements of the proteges.

Summary

1. The teacher asks a willing student to summarize the lesson from his point of view. He asks other students if they would like to add anything to their colleague's statements.

Homework

1. Develop a lap book containing issues learned during the lesson and bring your work to the next class.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Mixtures and their division

In everyday life, we rarely encounter pure substances, but often – their mixtures. These are, for example, tea, milk, medicines, sodas, gasoline, parrafin, toothpaste, jelly, ketchup, air or metal alloys, e.g. bronze.

Mixture is at least two substances that can be mixed together (physical process) in any proportions.

Components of some mixtures are not visible (saline solution in water), in others these are easily seen (sand with water). Given this criterion, mixtures can be divided into:

• homogeneous mixtures where components cannot be distinguished by the naked eye or by simple optical devices, such as a magnifying glass;

• heterogeneous mixtures, where components can be distinguished by the naked eye or by simple optical devices, e.g. magnifying glass.

Types of mixtures

Division of mixtures

• We meet different types of mixtures in vicinity.

• All mixtures consist of at least two components mixed together in any proportions.

• Mixtures such as water with chalk or smoke, the components of which can be distinguished with the naked eye, are called heterogeneous.

• Mixtures such as sea water, air or metal alloys, the components of which cannot be distinguished even with magnification, are called homogeneous.

mixture, substance, element, chemical compound, homogenous mixture, heterogenous mixture