The chemistry scenario

Elaborated by: Krzysztof Błaszczak

Target group:

Elementary school student (grades 7. and 8.)

Core curriculum:

Primary school. Chemistry.

III. Mastering practical activities. Pupil:

1. safely uses simple laboratory equipment and basic chemical reagents;

4. observes the principles of occupational health and safety.

Abstract title:

Chemistry lab, part 2

Link to the lesson:

https://www.epodreczniki.pl/reader/c/153030/v/latest/t/student‑canon/m/iIiSm0xKqrhttps://www.epodreczniki.pl/reader/c/153030/v/latest/t/student‑canon/m/iIiSm0xKqrhttps://www.epodreczniki.pl/reader/c/153030/v/latest/t/student‑canon/m/iIiSm0xKqr

Subject: What are the rules of working in the laboratory?

Duration: 45 min

Lesson objective:

The student justifies the need for special labeling of hazardous chemical substances and their mixtures as well as discusses the safety rules at the chemistry lab

The criteria for success:

• you will describe the meaning of the indicated pictogram

• you will identify the lab designations of substances that are harmful, corrosive, explosive, flammable, carcinogenic, toxic and harmful to the environment

• you follow the safety rules that must be observed in your chemistry lab

Key competences:

• communication in the mother tongue 

• communication in foreign languages

• mathematical competence and basis competences in science and technology 

• digital competence 

• learning to learn 

Teaching aids:

• computers with loudspeakers and Internet access

• multimedia resources included in the e‑textbook and abstract

• interactive whiteboard/chalkboard and chalk

• table tent or green, yellow and red cards

• multimedia presentation

Methods/techniques

• problematic: didactic discussion

• expository: lecture elements using a multimedia presentation

• exposing: the film

• programmed: using the computer, using an e‑textbook

• traffic lights technique for students’ self‑assessment, and thus determining the level of mastery of the discussed problem on an ongoing basis

Forms of work:

• individual activity

• activity in pairs

Lesson plan overview:

Introduction

1. The teacher distributes to the students table tents or cards in three colors: green, yellow and red to be used during the activity using traffic lights method. The teacher presents the lesson objectives in the student's language in the form of a multimedia presentation and discusses the criteria for success (the teacher can send lesson objectives and criteria for success to the students by e‑mail or post them e.g. on Facebook, which will allow the students to keep their portfolio).

2. The teacher and the students work together to determine the subject of the lesson on the basis of the previously presented lessons objectives and then writes it on an interactive whiteboard/chalkboard. The students write the subject down in their notebooks.

Realization

3. The teacher displays on the interactive whiteboard the safety rules applicable in the chemistry lab, and discusses them one by one. The teacher can also instruct students to read them from the drop down table in the abstract. The teacher displays an illustration that includes symbols of obligatory behavior in the chemistry lab (abstract) and encourages students to discuss.

4. The teacher presents the basic laboratory activities that should be carried out in accordance with the safety rules.

5. After discussing the principles of safety in the chemistry lab, the teacher refers students to the abstract and asks them to do interactive exercises individually.

6. The teacher informs the students in advance about the possible need to read the safety data sheets of the substances to be used for experiments during the given lesson, in order to observe the safety measures during the lesson. The teacher presents them with several such sheets, noting that some substances are marked with pictograms. The teacher then displays a multimedia presentation of the most important pictograms, discussing their meaning. The teacher asks to do interactive exercise 1 in the abstract.

7. The teacher discusses the risks of absorption of hazardous substances into the human body through the skin and respiratory tract, using an interactive illustration from the abstract.

8. The teacher refers students to the abstract in order to do other interactive exercises.

Summary

9. In the summary of the lesson, the teacher displays the summary sentences in the multimedia presentation and asks the students to finish them, e.g.:

• What was important for me…

• What I learned…

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

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Chemistry lab pt 2

How to properly perform basic laboratory activities?

Laboratory techniques are activities the mastery of which is a prerequisite for proper experimental work; the order in which they are performed is not arbitrary and knowledge of the activities is a necessary element for obtaining correct results and ensuring safety in the laboratory.

By conducting experiments in the chemical laboratory, we engage our senses, receiving specific stimuli that provide us with information about the phenomena we are studying. We must be particularly careful to ensure that the sensory organs are properly protected. The risk of dangerous substances being absorbed into the body through the skin, mucous membranes and respiratory tract must always be borne in mind.

Odors and sense of smell

What is commonly referred to as smell is in fact an odor impression, i.e. the ability of a substance to stimulate the olfactory organ. Depending on the experience and individual properties of a person, the description of a smell can be a single word or take the form of a specialist study (e.g. for the perfumery industry).

The proper olfactory organ is the olfactory epithelium located at the top part of the nasal cavity, constituting approximately 2 cmIndeks górny 2² area in each nasal opening. The olfactory cells come into contact with the air through a system of dendrites with cilia in which receptors are located, while the other end of the cell has access to the brain through its elongated part (3‑4 cm long axon). Interestingly, the sense of smell fades with age, but the cells themselves are renewed throughout the body's life.

How do we handle liquid substances in the laboratory?

• In the chemical laboratory the rules of health and safety must be followed.

• Use special glassware, dishes and laboratory equipment to perform chemical experiments.

• When planning an experiment, it is important to remember to use reagents rationally in order to reduce the amount of waste generated.

• Chemical experiments should be performed on the laboratory table in accordance with laboratory work techniques, bearing in mind the principles of health and safety and order.