Topic: Oxygen: obtaining

Target group

Student of an eight‑year elementary school

Core curriculum:

Elementary school. Chemistry.

IV. Oxygen, hydrogen and their compounds. Air. Student:

1) designs and performs an experiment to obtain oxygen and tests the selected physical and chemical properties of oxygen; reads from several sources (e.g. periodic table, solubility graph) information on this element; lists its uses; writes the equations for the reactions to produce oxygen and for the reaction of oxygen with metals and non‑metals;

6) describes the oxygen and carbon cycle in nature.

General aim of education

The student discusses the preparation, properties and use of oxygen

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to indicate the location of oxygen in the periodic table of elements;

• to give examples of the use of oxygen and oxides in everyday life;

• to plan and perform experiments to obtain oxygen and oxides.

Methods/techniques

• expository

  • talk.

• activating

  • discussion;

  • mind map;

  • brainstorming;

  • flipped classroom.

• 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 writes the password: oxygen on the board. During a brainstorming session, students give the information they know and the moderator writes it on the board in the form of a mind map. After the creative phase, the proposals are verified. The teacher ensures that information on, among others, air composition, and if necessary, ask auxiliary questions.

2. The teacher displays the periodic table of elements in the abstract on the interactive whiteboard, asking for an indication of the place of oxygen in it and discussing the structure of its atom.

3. The teacher uses the flipped classroom method – before the classes the pupils were given the task of preparing the content from the textbook and other sources of knowledge about the circulation of oxygen in nature. The trainer divides the students into groups and orders each preparation on the paper sheets of the oxygen flow diagram in nature. After finishing the work with the use of technique, the talking group faces the effects of actions; the teacher summarizes the speeches.

4. The teacher instructs students to get acquainted with the time axis presenting research on oxygen production; also asks for searching in various sources about the creation of the name „oxygen”. Willing/selected students summarize the information.

5. In reference to the issue of oxygen production, the teacher explains that oxygen in the laboratory is obtained by other methods – one of them they learn by watching the film „Extraction of oxygen and nitrogen from liquid air”. Before this happens, they are to formulate a research question and hypotheses - they are recorded in the abstracts of observation diaries. They follow changes, discuss their observations and then concretize conclusions.

6. The teacher – in the form of a teacher's show – conducts, according to the instructions in the abstract, the experience of „Obtaining oxygen from hydrogen peroxide with the participation of yeast”. As before, the students set the research question and hypothesis, write them in notebooks. They observe changes taking place during the show, they discuss and formulate conclusions.

7. The instructor divides the students into groups. Students using the available sources (e‑textbook, internet, etc.) develop information on the use of oxygen. Teams present the effects of activities.

Summary

1. The teacher asks the students to finish the following sentences:

   • Today I learned ...

   • I understood that …

   • It surprised me …

   • I found out ...

   The teacher can use the interactive whiteboard in the abstract or instruct students to work with it

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. Present in the form of a table physical and chemical properties of oxygen and nitrogen.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Oxygen: obtaining

Around 300 years ago air was still thought to be a chemical element or compound and not, as we know today, a gas mixture. Although nitrogen represents as much as 78% of the air volume, its exclusive presence in the atmosphere would mean total lack of life on Earth.

Oxygen is the most common element in nature. It accounts for almost half of the weight of the earth’s crust. It is a part of water, rocks, metal ores, sand.

Oxygen is essential for the life of most organisms, without it, animals and plants die. Decreasing its content in the air from 21 to 15% causes disruption of the body's work, and a drop below 10% may lead to death. Interestingly, in 2010, European scientists discovered the first larger multicellular organisms that do not need oxygen to live. Previously unknown species were found in sediments located in the seabed of the Mediterranean Sea.

Oxygen was discovered around 1774 by an Englishman Joseph Priestley and, independently, also by the Swede Karl Scheele. As a result of heating the mercury(II) oxide, gas was emitted and droplets of mercury were deposited on the walls of the vessel. The resulting combustion sustaining gas was oxygen. Watch the film from the e‑textbook, note the origin of the name “oxygen”.

In the laboratory, oxygen is obtained in a slightly different way.

• Oxygen is the most common element in nature.

• Oxygen is a colorless, odorless, slightly soluble in water, chemically active gas.

• Oxygen can be obtained during thermal decomposition of potassium manganate(VII), hydrogen peroxide decomposition (in the presence of a catalyst) or water decomposition due to an electric current (water electrolysis).

• The industrial method of obtaining oxygen is to distil liquid air.