Topic: Physical properties of the substances

Target group

Elementary school student (grades 7. and 8.)

Core curriculum:

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 substances.

3) describes the states of matter;

4) explains the phenomena of diffusion, dissolution, change of state of aggregation.

General aim of education

The student lists and determines the physical properties of the substances tested.

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.

Criteria for success
The student will learn:

• to indicate the states of substance aggregation in the context of their properties;

• to determine which properties of the substance are included in physical properties and which are chemical properties;

• to plan methods for testing the physical and chemical properties of substances.

Methods/techniques

• expository

  • talk.

• activating

  • discussion.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned;

  • experiment.

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. Students read the fragment Fri „Focus States”. They analyze the table and diagram illustrating the changes of the mental states. Then, working in pairs, they determine the state of focus of the objects around them.

2. The teacher announces a movie entitled „Solid or liquid”. Instructs students to write a research question and hypothesis in the form provided in the abstract. Displays the video, and students record their observations and conclusions. Volunteers read them. The teacher encourages young people to discuss, referring to the presented conclusions.

3. The teacher divides the properties of the substance into physical and chemical. He asks students to give examples of physical properties, and then presents illustrations from the abstract („Physical properties” and an example description of the physical properties of gold).

4. The teacher asks participants to read the experiment's instructions in the abstract (experience 1: „How can the physical properties of substances and their mixtures be identified?”). It divides students into groups and distributes the appropriate equipment, glass and reagents to perform the experiment. Students follow the instructions and the observations are presented in the form of a table, in accordance with the formula in the abstract. After completion of activities, group leaders present the effects of teamwork.

5. 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. Students, working in pairs, get acquainted with the content of the glossary and explain in own words the meaning of selected concepts.

2. 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. Carry out task number nr 5.1.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Physical properties of the substances

The substances may exist (at a certain temperature and at the appropriate pressure) in one of the three basic states of aggregation:

• solid

• a liquid,

• gas.

A change in the physical state of the substance is made at a specific temperature. Let's look at this phenomenon on the example of water.

Sometimes a solid substance transforms directly into gas, bypassing the liquid state (sublimation) and vice versa - the gas can directly go into a solid state without condensation or solidification (desublimation).

Physical properties physical - characteristics of the substance:

• state of aggregation;

• colour;

• type of surface: shiny, matt, rough, porous;

• hardness;

• change in the shape of the body under the influence of forces: brittleness (permanent deformation with disintegration into smaller pieces); resilience (change in shape under the influence of low force and return to its original shape); malleability (permanent deformation of metals, but without breaking down into smaller pieces);

• solubility in water and other solvents (liquid, solid and gas);

• heat conductivity;

• electrical conductivity;

• magnetic properties;

• boiling point;

• melting temperature;

• density.

• The world consists of various substances that have a permanent composition and specific properties.

• Substances can be identified based on their properties.

• Each substance has its own physical properties, eg physical state, colour, water solubility, and chemical, e.g. taste, odor, flammability.

• Substances may be present in three states of aggregation.

• The uses of substances result from their characteristic properties, both physical and chemical (eg sugar is sweet, so we use it for sweetening, carbon dioxide does not support combustion, so it is used as a fire extinguisher in some types of fire extinguishers).