Technological map of the lesson physics in 7th grade.

Laboratory work No. 2 "Determining the size of small bodies".

Subject		Laboratory work No. 2 "Determining the size of small bodies."
Lesson type:		A lesson in the formation of initial subject skills.
Target		ensuring the development of skills for measuring the dimensions of small bodies using the series method.
Tasks		Educational: 1. during the lesson, find out what methods exist for determining the size of small bodies; 2. to learn by experience to determine the dimensions of small bodies, including the dimensions of molecules from a photograph of a substance; 3. to deepen the theoretical and practical knowledge gained in the study of the topic “Structure of substances. Molecules. Developing: 1. awaken curiosity and initiative, develop a steady interest of students in the subject; 2. expressing his opinion and discussing this problem to develop students' ability to speak, analyze, draw conclusions. 3. contribute to the acquisition of the necessary skills for independent learning activities. Educational: 1. during the lesson, to promote the education of students' confidence in the cognizability of the world around them; 2. working in pairs of permanent composition, when performing experimental tasks and discussing the problem, to educate the communicative culture of schoolchildren.
Planned result. metasubject results. 1. the formation of cognitive interests aimed at developing ideas about the structure of substances; 2. ability to work with sources of information, including experiment; 3. the ability to convert information from one form to another. Subject results. 1. be able to use a ruler to measure physical quantities. 2. be able to express measurement results in SI units. 3.use the series method to measure small bodies.		Personal. Conscious, respectful and benevolent attitude towards another person, his opinion; willingness and ability to engage in dialogue with other people and achieve mutual understanding in it. Cognitive. Identify and formulate a cognitive goal. Build logical chains of reasoning. Produce analysis and transformation of information. Regulatory. Ability to plan research; identify potential difficulties in solving the educational problem; describe your experience, plan and adjust. Communicative. Ability to organize educational cooperation and joint activities with the teacher and peers; work individually and in a group: find a common solution and resolve conflicts based on the coordination of positions and consideration of interests.
Basic concepts of the topic		Molecule, measurement error, division value, series method.
Space organization
The main types of educational activities of students.	Core technologies.		Basic methods.	Work forms.	Resources.Equipment.
1. Listening to the teacher's explanations. 2. Independent work with the textbook. 3. Performing frontal laboratory work. 4. Work with handouts. 5. Measurement of quantities.	collaboration technology.		1. verbal; 2. visual; 3.practical.	Individual, general class, in pairs of permanent composition.	Physical hardware: ruler, beads, thin wire or thread, photo of molecules, pencil, needle, caliper or micrometer. Resources: tests, forms for l / r. No. 2, presentation.

Structure and course of the lesson.

	Lesson stage	Stage tasks	Activity teachers	Activity student		Time
Introductory-motivational stage.
	Organizational stage	Psychological preparation for communication	Provides a favorable mood.	Getting ready for work.	Personal
	Stage of motivation(determining the topic of the lesson and the joint goal of the activity).	Provide activities to define the objectives of the lesson.	He proposes to discuss the statement of the French physicist and the problematic issue and name the topic of the lesson, determine the goal.	They are trying to solve the problem. Determine the theme of the lesson and the purpose.
Operational and content stage
	Learning new material. 1) Updating knowledge. 2) Primary assimilation of new knowledge. 3) Initial check of understanding 4) Primary fastening 5) Control of assimilation, discussion of the mistakes made and their correction.	To promote the activities of students in independent study of the material.	Offers to organize activities according to the proposed tasks. 1) Offers to perform entrance testing. 2) Briefing on the performance of work. Explanation of theoretical material. 3) Offers to perform experimental tasks. 4) Offers to answer questions. 5) offers to draw conclusions.	The study of new material on the basis of independent laboratory work. 1) Run the test. 2) Listen. 3) Perform the proposed experimental tasks. 4) Answer questions. 5) draw conclusions. Discuss.	Personal, cognitive, regulatory
Reflective-evaluative stage.
	Reflection. (Summarizing).	An adequate self-assessment of the individual, his capabilities and abilities, advantages and limitations is formed.	Prompts you to select an offer.	Answer.	Personal, cognitive, regulatory
	Submission of homework.	Consolidation of the studied material.	Writing on the board.	Recorded in a diary.	Personal

Appendix.

motivational stage.

1. “Learning to measure correctly is one of the most important, but also the most difficult stages of science. One false measurement is enough to prevent the discovery of the law and, even worse, to lead to the establishment of a non-existent law. (Le Chatelier)

Discussion with students of the statement of the French physicist and chemist Henri Louis Le Chatelier. After discussions, students determine the topic of the lesson and formulate a goal.

2. You know that molecules are unimaginably small. Even at the tip of a mosquito sting, with an area of ​​​​about 10-12 cm2, tens of thousands of water molecules can fit. Despite this, scientists were able to determine the size of the molecules. How? Discussion. Answer, guess. I suggest you do the experiment yourself to determine the size of the molecules.

2. Learning new material.

Input control.

Target: motivation of educational activity and actualization of students' knowledge.

Test.

Subject: Molecules. Molecule sizes

1. The price of division of the device -
1. this is the distance between adjacent divisions on the scale of the instrument, expressed in units of the instrument.
2. this is the distance between adjacent divisions, indicated by numbers on the scale of the instrument, expressed in units of the instrument.
3. this is the minimum value that the instrument can measure.
4. this is the maximum value that the instrument can measure.
2. The molecule is
1. the smallest particle of a substance that determines its chemical properties.
2. the smallest indivisible particle of a substance that determines its chemical properties.
3. the smallest particle of a substance that determines its physical properties.
3. The molecule is characterized by:
1. mass,
2. size,
3. composition of atoms
4. structure
4. Molecules can be seen with:
1. optical microscope,
2. telescope,
3. magnifying glass,
4. electron microscope
5. An electron microscope magnifies:
1. 100,
2. 100 000,
3. 1000
6. From a photograph of a substance, you can determine the diameter of a molecule:
1. true,
2. visible,
3. false
4. hidden
7. The true size of a molecule can be determined by knowing the microscope magnification using the formula: d = D / k d = D * k d = D + k
8. The average true molecular size is: 1mm, 0.00001mm, 0.0000001mm
9. A drop of oil was dropped onto the surface of the water. Which of the statements is true.
1. The thickness of the oil film can be arbitrarily small,
2. the thickness of the oil film cannot be less than the size of the oil molecule,
3. oil molecule size can be 0.1mm,
4. oil molecule size can be 0.0001mm
10. To determine the size of small bodies, the following are used:
1. Ruler
2. Calipers
3. Micrometer
4. body photography

Form of laboratory work No. 2

Class ______ Last name ____________________Name_______________The date______

Laboratory work No. 2 "Determining the size of small bodies"

Targetworks: learn to determine the size of small bodies using a ruler.

Equipment: ruler, beads, thin wire or thread, photo of molecules, pencil, needle.

Experience scheme: (make drawings)

Calculation formulas: (write down the formulas you need)

Work progress (table for measurements)

		n quantity particles in a row	row length,	particle size	error
	wire
	wire
	molecule in the Foto
	molecule

Exercise 1. Determining the diameter of a bead of beads (use a needle to make a row).

Exercise 2. Determining the thickness of the wire (use a pencil to wind coils of wire or thread)

Exercise 3. Determining the true size of a molecule

Determine the size of the molecule using the series method from the photo in the textbook.

Using the magnification of the microscope given in the text of the textbook, calculate the true size of the molecule in mm.

Enter the data in the table.

Convert mm to nanometers (1 nm= 0.000000001m, 1mm= 0.001m).

Draw your own conclusions by answering the following questions:

1. what method was used to measure the size of small bodies in the laboratory work.

2. what determines the accuracy of measuring the dimensions of small bodies when using this method.

3. Name the devices known to you for measuring the dimensions of small bodies.

4. What are the dimensions in nanometers of a protein molecule in a photo in a textbook.

An additional task of an increased level.

Using a caliper or micrometer, measure the diameter of the bead and the thickness of the wire. Compare the results obtained with similar data using the series method.

Draw your own conclusions.

3. Reflection.

Choose an offer.

I understood everything very well.

It was interesting to me.

I understand everything, but the material is not always interesting.

I didn't understand everything, but I was curious.

I did not understand anything and was bored in class.

Laboratory work number 2.

Objective

Devices and materials

______________

Reference words: kg, s, m, m/s, m2 , m3 ,◦C.

row method.

Calculations: where d is the diameter, l is the row length, n is the number of particles in the row,

Working process

	Body (particle)	Number of particles in a row, n	row length,	Single particle size
	molecule		in the Foto	true

Work output: _______________________________________________________________________________

Evaluation: _________ Date: __________ Work checked

View document content
"Laboratory work No. 2"

http://www.myshared.ru/slide/1247114/presentation

Laboratory work number 2.

Measurement of the sizes of small bodies.

Objective: learn how to measure using the row method.

Devices and materials: ruler, peas, millet, needle.

Training tasks and questions

1. Is it possible to accurately measure the diameter of a wire, thread, hair using a ruler? Why?

2. To measure the diameter of the wire, wrap 30 turns of it tightly around the pencil. Determine the wire diameter.

Wire diameter ___________________________________.

3. A stack of 20 coins turned out to be ______________ cm high.

The thickness of one coin is ________________________________.

4. Compare physical quantities and their units:

Length_______________ temperature _______________ mass _______________ speed ____________

Time _______________ area ________________ volume ______________

Reference words: kg, s, m, m/s, m2 , m3 ,◦C.

The way you determine the (body size) wire diameter and coin thickness is called row method. It is in this way that you will determine the diameter of the pea and millet.

Calculations: where d is the diameter, l is the row length, n is the number of particles in the row,

Working process

1. Determine the division value of the ruler C.d. = _____ mm

2. Place 15 peas in a row close to the ruler. Measure the length of the row and calculate the diameter of one pea.

3. Determine the size of a grain of millet in the same way. For convenience, use a needle and a thin pencil rod.

4. Determine the diameter of the molecule, if in the photograph (70,000 times magnification) 10 molecules occupy

5. Enter the results of measurements and calculations in the table:

	Body (particle)	Number of particles in a row, n	row length,	Single particle size
	molecule				in the Foto		true

6. Look at the picture of the molecule in the textbook. Determine the size of the particles, if the magnification is 70,000 times, the number is 10 molecules and they occupy a length of 2.8 cm.

Number of particles in a row _________pcs. Row length ________ mm = __________ cm = _______ m

Particle diameter in the photo _______mm ​​= _______ cm = _______ m

Photographic magnification ______ times Actual particle size _______ mm = ______ cm = ____ m

Work output: _______________________________________________________________________________

___________________________________________________________________________________________

Evaluation: _________ Date: __________ Work checked by: ___________

If you need to determine the dimensions of a very small body (even a poppy seed), and this cannot be done using measuring instruments (for example, a ruler), you should resort to the "series method".

Arrange a number of bodies close to each other in a row, measure the length of the row and calculate the size "l" of one body using the formula.

N - number of bodies in a row
L - row length

Check it out, don't be lazy, it's very convenient!

Perform work on 3 options (see figure) in notebooks for laboratory and testing work. Time to complete the job is 20 minutes.

Prepare work in accordance with the school standard:

Lab No.

Goals of the work:

Devices and materials:

Completing of the work:

Answer the control question in writing.

Test questions:

Suggest a method for determining the size of molecules in this way.

Basic provisions of the ICB

Molecular-kinetic theory is the study of the structure and properties of matter based on the idea of ​​the existence of atoms and molecules as the smallest particles of chemical substances.

The molecular kinetic theory is based on three main provisions:

1. All substances - liquid, solid and gaseous - are formed from the smallest particles - molecules, which themselves consist of atoms ("elementary molecules"). Molecules of a chemical substance can be simple or complex, i.e. be made up of one or more atoms. Molecules and atoms are electrically neutral particles. Under certain conditions, molecules and atoms can acquire an additional electrical charge and turn into positive or negative ions (dissolving a grain of salt in water, distributing particles of a drop of paint throughout the volume of a liquid, ...)

2. Atoms and molecules are in continuous chaotic motion (Brownian motion, ...)

3. Particles interact with each other by forces that are electrical in nature. The gravitational interaction between particles is negligible()

Rice. Brownian particle trajectory

The speed of movement of gas molecules. In gases, complete chaos reigns, molecules move in all directions with a variety of speeds.

Let's calculate, for example, the average speed of gas molecules in the classroom:

T=300K, mo=M/Na, M=0.029 g/mol. With this in mind, we have:

D.Z.: 1. Give 2 examples to prove each provision of the MKT (in writing).

2. Answer in writing the question 2.4 in the text. Illustrate your answer to question 4 with a picture.

3. Compose and solve a problem similar to the one above.

The purpose of the lesson:

• introduce students to various ways to measure the size of small bodies
• repeat the techniques for determining the error and recording the measurement result

Tasks:

Subject:

• form the concept of measuring the dimensions of small bodies;
• correctly interpret the physical meaning of the quantities used, their designations and units of measurement

Metasubject: improve students' skills in

• monitoring,
• planning and execution of the experiment,
• processing of measurement results,
• presentation of measurement results using tables and formulas,
• explanations of the obtained results and conclusions,
• estimation of measurement errors.

Personal:

• form cognitive interest, develop intellectual and creative abilities of students;
• develop independence in acquiring new knowledge and practical skills;
• to increase the motivation of schoolchildren to study the subject on the basis of a personality-oriented approach.

Lesson type: lesson on improving knowledge, skills and abilities

Forms of student work verbal, use of information and communication technologies, frontal work

Required technical equipment: computer, multimedia projector; class with PC, electron microscope, caliper, worksheet, material for experiments: ruler, peas, needle, thin wire, grains of semolina, pencil, metal ball.

DURING THE CLASSES

1. Organizational moment

Good afternoon dear guests, hello guys. Please sit down.

2. Motivational stage

Guys, today we are conducting the last lesson in the study of the section "Initial information about the structure of matter" and you have come to our today's meeting already quite prepared. You are familiar with some terminology and have a little idea of ​​physics as a science of nature that studies physical phenomena. Let us now try to prove this to our guests in practice.

Choose from those words that now appear on the screen those that relate to the concept of the physical body.

And now, please, try to determine from the words that have reappeared on the screen which of them are related to the concept of substance?
Man began to think about physical phenomena a very, very long time ago. It must have happened when he first looked up at the sky, when he saw a stone fall, or maybe when he managed to light a fire for the first time. The very first way to study nature was observation.

And then a thought arose in a person’s head, what would happen to the phenomenon if the conditions of its origin were changed. Thus arose the second way of studying nature - experience.

When setting up an experiment, a person uses various physical devices. Each device has its own purpose, but they all have one thing in common - they have a scale. The scale determines the value of a physical quantity. For example, a ruler - length, scales - mass, stopwatch - time.
In order to determine the true value of a quantity on a scale, it is necessary to first determine the division price, i.e. the smallest value defined by the scale.

Tell me, using an example with a thermometer, how to determine the division value? What will it be equal to? In order to work with any physical device and use it to take readings of a physical quantity, the ability to determine the division value is still not enough. With any measurement, we have the right to a certain measurement error, the so-called error. How to determine the error? What meaning is taken for it? Let's look at an example of recording a measurement of the length of a pencil, taking into account the error.
At the beginning of the study of this topic, we have already conducted an experiment to determine the length of the table, measure the temperature of the water. These seemingly diverse measurements have one thing in common - the value of the measured physical quantity was greater than the scale division of the measuring device.
With the help of a ruler, we can easily determine the height of the bar, the length and width of your table, notebook. A table, a bar, a notebook are quite large bodies when compared with a hair, a pea or a grain of buckwheat.

What do you think, is it possible to use your ruler to determine the diameter of the thread, the thickness of the sheet, the dimensions of small bodies, for example, the molecules of a substance? It's probably possible. Why is this necessary, you ask? Where can these skills come in handy? I can say that measuring skills are needed in almost many professions, such as a turner. Turner - grinds a part to order, if he makes a mistake in size, then his part will be rejected. We can form the ability to measure the linear dimensions of small bodies already at this stage, studying at school.

3. Indicative stage

Today we have to explore new ways to determine the size of small bodies. But first, answer me one more question: how is experience different from observation?
Guys, what would be your goal today? What would you like to know, what to make sure? (Students set goals, and the teacher fixes their proposals on the board)

To achieve your goal, I have developed a number of technical tasks, you will now be divided into groups and after completing it you will demonstrate your result. ( Appendix 1 )

4. Performing stage

And now, guys, you can start doing the lab. Let the motto for you today be the words of Shota Rustaveli “If you don’t act, there’s no point in the chamber.”
Good luck!

5. Control stage

The guys demonstrate their results through the webcam, the teacher sums up the methods used

6. Reflective stage

I suggest that the guys answer the questions that are written on the sheets. ( Annex 2 )

7. Final stage

Today we have considered new ways of measuring the size of small bodies, thereby achieving the intended goal, consolidating the knowledge gained earlier.
I hope you understand that "no one knows as much as all of us together."
Thank you for the lesson!
Submit worksheets. The lesson is over.

The author of the presentation "Measuring the size of small bodies" Pomaskin Yury Ivanovich - teacher of physics, Honorary Worker of General Education. The presentation was made as an educational visual aid for the textbook "Physics 7" by A.V. Peryshkin. Designed for demonstration in the lessons of studying new material Sources used: 1) A.V. Peryshkin "Physics 7", Moscow, Bustard str) Pictures from the Internet (

Directions for work 1. Place several pellets in a row close to the ruler. Count them n = 14 pieces

Instructions for use 2. Measure row length mm n = 14 pieces

Directions for work 3. Calculate the diameter of one pellet mm n = 14 pieces d = 23 mm 14 = 1.64 ... mm

Directions for work Determine the diameter of the molecule in the photo using the row method. n = mm d = =1.3 mm 13 mm 10

Instructions for work The magnification in the photo is 70000, which means the true size of the molecule is several times smaller than in the photo. 8. Determine the true size of the molecule d = = 0, .... mm 1.3 mm and

Instructions for the work of the experiment Number of particles in a row Length of a row (mm) Size of one particle d, mm 1. Fraction 2. Peas 14231.64 ... 3. Molecule 1013 In the photo True size 1.30, ... 9. Enter the data of the experiment in the table.