Fascinating experiments with light in the laboratory of Professor Know-It-All. Properties of transparent bodies

Luminous and non-luminous bodies

To study issues related to color, it is often important to know certain properties of the objects around us. First of all, we note that all of them can be divided into luminous and non-luminous bodies. The color and intensity of most light sources depend on their filament temperature. In cartography, the use of substances emitting “cold” light is becoming increasingly important. Luminescent compounds are used in the preparation of some maps for publication; with their help, some flight maps are created (for night flights). There are obvious great prospects for the use of luminescent compositions in the design of school, demonstration, and propaganda cards. However, the issues of using luminescent compounds in the design of cards have not been sufficiently developed, and very few cards using luminescent compounds have been created.

There are many times more non-luminous bodies than luminous ones. The color of such bodies depends on how they absorb, transmit or reflect light falling on them.

Transparent and opaque bodies

Bodies are considered transparent if light can pass through a significant thickness of them, opaque - bodies through whose thickness light does not pass. Note, however, that there are no perfectly transparent or perfectly opaque bodies. The color of an opaque body is determined by the rays that are reflected from it. The color of transparent bodies, when viewed in the light, is determined by the rays passing through the body.

Paints can also be transparent ( glaze) or opaque ( coverts). The covering power of paints, as well as their transparency, depends on the ratio of the refractive indices of the pigment and the binder (the medium surrounding the pigment particles). The higher the refractive index of the pigment relative to the binder, i.e., the relative refractive index, the more light will be reflected from the surface of the pigment particles at the boundary of these two media and the less light will penetrate deep into the particles.

For example, the good hiding power of titanium white (oil paint) is explained by the fact that the difference between the refractive indices of the pigment (2.7) and oil (1.5) is significant. The refractive index of chalk is 1.6, and to get a good covering paint, you need to dilute it not in oil, but in water.

The color of the paint we see is determined by the total rays acting on the eye, some of which were reflected from the surface itself (these are “white” rays), others from the pigment particles in the top layer of paint (these rays passed through a small layer of pigment particles and are weakly colored), the third - from pigment particles located deeper and colored more strongly and, finally, by rays that passed through the entire layer of paint and reflected from the substrate (for example, paper). Without considering the complex phenomena of reflection, transmission and absorption in the paint layer, we note that the most saturated, pure colors can be obtained with transparent paints, that is, paints in which the pigment and binder have similar refractive indices. Light penetrates deeper into a layer of transparent paint and the degree of selectivity of absorption will be greater. Therefore, transparency is one of the important conditions for inks for printing cards (especially their background elements).

Reflection from surfaces

In cartography, it is often necessary to take into account the reflective properties of surfaces. All surfaces, according to their properties, are usually divided into shiny, glossy and matte.

From shiny (very smooth) surfaces, rays are reflected directionally, according to the law “the angle of incidence is equal to the angle of reflection.” Matte (rough) surfaces reflect rays scatteredly in all directions. Glossy surfaces have intermediate properties.

With a matte surface texture, rays of “white” light, which have not yet had time to penetrate into the paint layer and are reflected from the surface, are mixed with the colored rays coming from the paint layer, and reduce the color saturation, making it somewhat whitish.

If a colorful work is placed under glass or its surface is coated with a transparent varnish, some of the rays of incident light will be reflected from the smooth surface of the glass (varnish) at a certain angle. And if the observation point is chosen so that these rays do not hit the eye (otherwise a glare will be visible, interfering with perception), the viewer will see cleaner, more saturated colors than with a matte surface texture. When printing on smooth paper, such as coated paper, the colors look cleaner and “richer” than on rough paper. Therefore, good reproductions of works of art are printed on coated paper, artists coat their paintings with varnish or place them under glass, photographs, in particular color ones, are “glossed”, etc. That’s why cards, if they want the colors to look more “rich” ", placed under glass (for example, in museums and exhibitions) or varnished. For example, maps in the atlas “Industry of the USSR at the beginning of the 2nd Five-Year Plan” (1934) were covered with varnish, which significantly improved their appearance. The same effect, in principle, is achieved by pressing on a transparent film when publishing cards using modern technology.

Change in color of adhesive paints when drying

The change in color of adhesive paints, such as watercolors, when drying is explained by a change in the relative refractive index. When drying, the water that filled the space between the pigment particles is replaced by air. The refractive index of pigment relative to air is greater than that relative to water, resulting in an increased proportion of light reflected from the surface of the pigment particles. An increase in the proportion of this “white” light in the total flow coming from the paint explains a slight increase in its lightness and loss of saturation. The second reason for this color change is that the smooth surface of wet paint after drying becomes rough, matte, the light will no longer be reflected directionally, but scatteredly and will reduce color saturation.

Change in color of paints when mixed with white

Media containing particles in suspension that obstruct the passage of light are usually called turbid media. Examples of such environments include the earth's atmosphere, diluted milk, and colorful mixtures are turbid environments. It is characteristic that rays of the long-wave part of the spectrum pass better through turbid media, while short-wave rays are strongly scattered. Therefore, if you look at the lumen (in transmitted light), turbid media acquire a warm color, since “some of the short-wave rays of the spectrum were scattered and did not enter the eye. In reflected light they have a bluish (cold) color due to the influence of scattered short-wave rays.

When white is added to paint, its lightness naturally increases and its saturation decreases. However, some paints noticeably change their color tone - towards a cooler color. Thus, the color of purple paints changes towards violet, green paints mixed with white paints turn blue, mixtures of black and white paints usually give a cold, bluish-gray color. This is explained by the fact that the paint mixture with white becomes an even more turbid medium, which strongly scatters short-wave rays, the addition of which changes the color tone.

If you want to make the paint lighter, you need to keep in mind that diluting it and mixing white into the paint lead to different results.

Color change when changing the spectral composition of lighting

The reflective properties of an object are objective properties and can be considered constant. Therefore, when the spectral composition of the light incident on an object changes, the composition of the reflected light will also change. White paper, for example, when illuminated by a red flashlight, will appear red; a green drawing on white paper will, under such lighting, appear black on a red background.

The light of incandescent electric lamps is noticeably different in its spectral composition from daytime “white” light. Daylight contains more blue rays, and artificial evening light contains more yellow rays.

Curves expressing the spectral characteristics of paints (see Fig. 87) are constructed under the condition of illumination with ideal white light, the spectral characteristics of which are depicted by a straight line parallel to the abscissa axis. When illuminated with a different light, the color of the painted surface will change, which means the curve that characterizes it will also change.

Examples of color changes under electric lighting compared to daylight:

By color tone: orange - blush; blue ones turn green; blue (some) - turn red, i.e. become closer to purple; violet - turn red (approaching purple).

By lightness: red, orange, yellow - lighten; green, blue, dark blue, violet - darken; yellow-green - do not change.

By saturation: reds become more saturated; orange - too; light yellow - turn white (difficult to distinguish from white); blue - lose saturation.

When working with paints, it must be borne in mind that their colors, when viewed in daylight, under incandescent lamps, under the light of arc lamps or mercury lamps, will differ noticeably in accordance with the selective properties of each paint, therefore, they will also look different color combinations. For example, green and blue colors, so often found side by side on maps, are better distinguished in daylight than in electric light. This may explain the fact that on some maps the coastline is not clearly visible under electric lighting.

To imagine during the day how the color combinations will look under electric lighting, the work must be viewed through orange-yellow glass.

It is useful to know, for example, that stains, runs and other defects in the coloring of cyan or dark blue paint will be more noticeable under incandescent light (as the blue and blue darken), whereas in daylight the seas and oceans will appear painted more evenly. Defects in the application of yellow and orange paints, on the contrary, will be more noticeable in daylight.

It is better to work with paints in daylight conditions or under fluorescent lamps. for the work of cartographers, artists, proofers, printers, receivers and other specialists working with paints, they must meet certain standards and be permanent.

Changing the color of objects as they move away

When viewing objects from a great distance, the rays reflected from them on their way to the eye pass through a significant thickness of the atmosphere, which is a turbid environment. Encountering on its way many different particles in the atmosphere (gas molecules, microorganisms, water vapor, dust particles, etc.), some of the rays are scattered in the air, deviating in different directions, and do not reach our eyes. This explains, for example, a decrease in the lightness of illuminated mountain slopes, and when viewing mountains from above, for example from an airplane, the lower lightness of low areas of illuminated mountain slopes. If we consider black or very dark objects located far away, they appear lighter due to the light scattered in the atmosphere (after all, almost no light is reflected from dark objects). This explains, for example, the lightening of low sections of mountain slopes on the shadow side (when viewed from above). They are highlighted by the light of the atmosphere, “air haze”.

All objects that are very light when viewed close up will appear less light at a great distance, for example on the horizon, while dark objects up close will appear lighter at a great distance. There is a sort of smoothing out of light contrasts.

The scattering of light depends on the diameter of the particles encountered in the medium, and rays of different will lengths are scattered differently. The rays of the cold part of the spectrum are scattered more strongly. It has been established, for example, that with a particle size of 0.1 microns, violet rays are scattered 9 times more than red ones. The blue color of the sky is explained by the fact that we see rays of the short-wavelength part of the spectrum scattered in the atmosphere. We see the reddish color of the evening or morning dawn because short-wave rays, traveling a much longer path in the atmosphere than during the day (when the sun is high), are scattered to a large extent, and mainly long-wave (red, orange, yellow) rays reach the observer .

If we consider, for example, the snowy peaks of mountains located on the horizon, their illuminated slopes will seem pinkish to us (generally warm), while the shadow sides acquire a cold color, for example blue, due to the mixing of rays from the short-wave part of the spectrum scattered in the atmosphere.

The scattering of rays in the atmosphere also explains the fact that the difference in the color of objects at large distances will be less noticeable than close up, since all colors will look less saturated, and the difference in lightness and color tone will be less noticeable. At very great distances the eye can no longer distinguish a large number of color tones; there is a kind of generalization of them to the point that the eye is able to distinguish only one warm or cold color.

When observed from long distances, the change in the color of objects and the decrease in the clarity of their outlines, associated with the scattering of rays in the atmosphere, is called aerial perspective.

This phenomenon is widely taken into account when constructing certain types of hypsometric scales and when designing individual, for example, picturesque landscape maps. Some general principles for the distribution of shadows in the cut-off design of the relief are based on it; taking this phenomenon into account, multi-color relief washing is also performed.

What colors belong to the short-wave color group, medium-wave color group, and long-wave color group?

Properties of transparent bodies. Properties of opaque bodies?

Light and color in nature

Light is visible radiation, i.e. electromagnetic waves in the frequency range perceived by the human eye.

Color is one of the properties of the material world, perceived as a conscious visual sensation. This or that color is “assigned” by a person to objects in the process of their visual perception. In the vast majority of cases, the color sensation arises as a result of exposure of the eye to streams of electromagnetic radiation from the wavelength range in which this radiation is perceived by the eye (visible range - wavelengths from 380 to 760 nm).

The flow of radiant energy, falling on the surface, partially penetrates deep into the body and fades as it penetrates into the thickness, and is partially reflected from the surface. The degree of extinction depends on the characteristics of the radiation flux and the properties of the body in which the process occurs. In this case, they say that the surface absorbs the rays.

Depending on the distance to which the light beam penetrates deep into the body before complete extinction, All bodies are conventionally divided into transparent, translucent and opaque. Only vacuum is considered absolutely transparent to all rays. Transparent bodies include air, water, glass, crystal, and some types of plastics. Metals are generally considered opaque. Porcelain, frosted glass - translucent bodies.

A substance or medium is called “transparent” if objects can be seen through this substance or medium; in this sense, a transparent substance is called, therefore, one that transmits, without absorbing or scattering, rays of all or some wavelengths acting on the retina of the eye. If a substance freely transmits all or almost all the rays of the spectrum visible to the eye, such as water, glass, quartz, then it is called “completely transparent”; if only some rays of the spectrum pass freely, while others are absorbed, then such a medium is called “transparent colored”, since, depending on the rays transmitted by the medium, objects viewed through it appear to be colored in one color or another; such as, for example, colored glasses, a solution of copper sulfate, etc. It is possible, by appropriate treatment, to change the degree of radiation of the medium without changing the nature of the rays transmitted by it; so, for example, by making the surface of a glass plate matte, that is, by covering it with a network of small irregular edges that reflect and scatter light, one can prepare a “translucent” plate through which the outlines of objects will be barely visible; By adding to a transparent medium a fine powder of a substance of a different refractive index suspended in it (milk glass, emulsions) or by soaking an almost opaque substance with liquid (paper impregnated with oil; mineral hydrophane impregnated with water), we obtain a “transparent” medium through which no The contours of objects are already visible, but the presence of light sources also differs. The power of a medium is thus determined primarily by the amount of light rays absorbed and scattered when passing through the medium; the latter depends on the thickness of the medium, increasing as the thickness of the path traveled by the rays increases.

Very thin layers of opaque substances (thin layers of metals) transmit some light, but thick layers of even very transparent bodies (water) can be opaque. The absorption coefficient for a given substance depends on the wavelength of the transmitted light and for rays of different wavelengths for the same substance can be very different.

Bodies can be transparent or opaque. Reflection, absorption, transmission - can only occur when transparent objects are illuminated. A certain color of an object is fixed by the eye after the interaction of light with this object, depending on the wavelength of the reflected color.

This is how a white sheet looks white because it reflects all the colors. A green object reflects predominantly green rays, a blue object reflects blue rays. If an object absorbs all the light falling on it, then it is perceived as black

The air environment retains and scatters some of the violet, blue, cyan rays, transmitting the rest almost without interference. Hence the result - a blue sky above our head. Morning and evening dawns are painted in warm colors, since sunlight, breaking through a thicker layer of the atmosphere, loses many cold rays. And the snow on the tops of mountains illuminated by the sun appears pinkish, due to the fact that the bright light reflected by the white surface also loses some of the short-wave (cold) rays on its way to us.

Reflection of rays. A ray of light falling on a smooth surface is reflected from it at the same angle, i.e. The angle of incidence of the beam is equal to the angle of its reflection. Based on the nature of the reflection of light rays, surfaces are divided into mirror, glossy and matte.

Mirror surfaces reflect almost the entire beam flux at the same angle to the surface without scattering it.

Glossy surfaces, such as those painted with enamel paints, reflect a significant portion of the rays in a direction close to specular, somewhat scattering them. An example of this kind of surfaces are surfaces painted with enamel paints.

Matte surfaces scatter light rays as a result of some roughness (for example, fresh dried plaster, a wall coated with adhesive paint, unpainted wood).

MINISTRY OF DEFENSE OF THE RUSSIAN FEDERATION

STATE PRESCHOOL EDUCATIONAL INSTITUTION

Preschool educational institution No. 74\106 "FAIRY TALE"

ABSTRACT

joint educational and research activities

older children and parents

TOPIC: Exciting experiments with light in the laboratory

Professor Know-It-All.

Conducted by: teacher

Gorbunova T. G.

Program content: introduce children to how a light beam can be seen; understand that light moves in a straight line and when something blocks its path, the rays of light stop and do not pass further; demonstrate the movement of the Earth around the Sun through the movement of the shadow; understand how a shadow is formed, its dependence on the light source and the object; learn that a shadow on a wall will be brighter and clearer if the light source is closer to the wall, and vice versa; introduce children to reflection, that reflection occurs on smooth shiny surfaces, and not only in light. Develop skills of coherent speech, speech hearing, thinking, visual attention and perception. Foster independence and activity.

Material. Globe, table lamp, flashlight, two square sheets of cardboard, two bookends, buttons, several books; ruler, toy (machine), sheet of paper, transparent sheet of plastic; a small mirror, black paper, a transparent rectangular container, water, milk; black cardboard, scissors, pencils, glue, brushes, brush stands, stencils, shadow theater screen.

Preliminary work. Conducting various experiments in the laboratory. Organization of observations of the sun, moon, stars, and candles. Games with shadow. Shadow theater show.

Progress of the activity process:

Children and their parents enter the music room and are greeted by Professor Know-It-All.

Good evening. I am very glad to see you in my laboratory. I'm Professor Know-It-All. Tell me, guys, what is a laboratory and what do they do in the laboratory? (Children's expected answers - In the laboratory, various experiments are carried out on animals, plants, etc.)

That's right, and today we will also conduct experiments and experiments, only with light.

Tell me, guys, what time of day is it now? That's right, evening.

What time of day do you come to kindergarten? What

do you do at night? What do you do during the day? (children's answers).

Why do you think day gives way to night, and when day passes, morning comes, and then day again? (children's answers). What light sources, besides the sun, do you know? (Moon, stars, lamp, lantern, candle, fire, etc.). Okay, now let's imagine that the table lamp is the sun, and the globe is our planet Earth. Now we will see how the change of day and night occurs.

The experiment is conducted by Professor Know-It-All.

1. Turn on the table lamp and direct the beam of light at the globe (turn off the lights in the room).

2. Turn the globe in different directions in the beam of light.

Conclusion (kids do): Only that part of the globe that receives the light is illuminated at all times. No matter how you turn the globe, its reverse side always remains in shadow. This means that the side that is illuminated by the sun is day, and the side that is in the shadow is night.

Professor's addition: The sun's rays travel in a straight line: they cannot bend around an object and illuminate the opposite side. Therefore, the Sun in turn illuminates only that side of the Earth that is now facing its rays. At this time, the other side of the Earth is in shadow.

And now, guys, together with your parents, you will try to prove why a beam of light cannot illuminate all sides of an object. Find out what a shadow is and why it changes shape.

We will explore the mysteries of light to understand how it spreads, what obstacles can stop it, and what obstacles it can overcome.

I propose to divide into two subgroups. One subgroup will be laboratory assistants and will conduct experiments, and the other will be trainees, they will make figures for the shadow theater.

Children and their parents go to the tables and select the necessary materials and aids. Parents and children conduct experiments, draw conclusions, sketch the results, and make figures for the shadow theater. Professor Know-It-All helps and gives advice. Then the parents and their children take turns coming out and showing each of their experiences. They draw conclusions.

The light is movingBydirect.

The experiment is carried out by Yulia A. and her mother.

Material: a flashlight, two sheets of cardboard, two cardboard stands, several books, a button.

Progress of the experiment.

Make a hole in the center of each cardboard. Place the cardboards on stands so that the holes are at the same height. Place a flashlight on a stack of books. Its beam should fall on the hole of the first cardboard. Stand on the opposite side. The eye should be level with the hole of the second cardboard.

Result. Through both holes you see light

Then move one of the cardboards so that the holes do not lie in line with the eye and the flashlight.

Result. The light is not visible.

Conclusion. Light travels in a straight line. When something blocks its path, the rays of light stop and do not pass further.

Eye exercise« Butterfly»

2.Opaque, transparent and translucent objects.

The experiment is carried out by Yulia E. and her mother.

Material: A book, a sheet of paper, a transparent sheet of plastic, black cardboard, a flashlight.

Progress of the experiment.

Place all the items one by one in front of the screen. Shine a flashlight on each item.

Result. A shadow forms behind the book and behind the cardboard. While there is no shadow behind a sheet of plastic. A blurry image appears behind a piece of paper.

Conclusion. A book, cardboard are opaque objects. This means that light cannot pass through them. As soon as rays of light fall on an “opaque” object, a shadow is formed behind it. Paper is a translucent object; some light can pass through it. Therefore, a blurry shadow is formed behind it.

3Shadow formation.

The experiment is carried out by Katya K. and her dad.

Material. Table lamp, flashlight, toy (car), animal figure cut out of cardboard (dog).

Progress of the experiment. Place the figure of the dog between the screen and the light source, alternately bringing the figure closer to the wall and then to the light. Do the same with a toy car.

Result. The closer the toy is to the lamp, the larger its shadow on the screen. The further the figure is from the lantern, the smaller its shadow will be

Conclusion. If any object blocks the path of the light beam, a shadow forms behind it. The rays fan out from the source. Therefore, if an object is located close to a light source, it will block less light and its shadow will be small.

4. Reflection of light.

Physical exercise. "Games with sunbeams."

After physical exercises, the teacher asks: “What do you guys think, where do the sunbeams come from?” (children's answers). That's right guys, when light rays come into contact with a smooth reflective surface (like a mirror), they are reflected.

Have you ever seen your reflection in water? How are clouds or trees reflected in water? (Yes). Yes, guys, water also has the property of reflection. Based on this, we will conduct the following experiment.

5. Bending light.

The experiment is carried out by Nikita P. and his mother.

Material. A transparent container with smooth rectangular walls, a flashlight, black paper, water, milk, a button, a book.

Progress of the experiment. Fill the container with water, add a few drops of milk (in this case the light beam will be brighter). Cover the flashlight with black paper, making a hole in the center of it with a button. Turn off the lights. Shine a flashlight at a container of water at an angle.

Result. When a beam of light passes through a container, it is reflected at an angle from the surface of the water. It turns out that a beam of light comes out of the container from the opposite side.

Conclusion. When light moves through water, it travels in a straight line. But the surface of the water behaves like a mirror, so some of the light is reflected at an angle.

Many thanks to all laboratory assistants for such interesting experiments. Now let's see what the trainees have prepared for us. (Figures of fairy-tale characters for the shadow theater).

Shadow theater showaccording to a fairy tale"Kolobok"(Nastya K. with mom)

You see, guys, how much we learned today. And now you can independently act out various situations, show fairy tales using shadows.

Thank you very much to everyone for working in Know-It-All's lab. See you soon.

Magnifier, microscope, telescope.

Question 2. What are they used for?

They are used to enlarge the object in question several times.

Laboratory work No. 1. Construction of a magnifying glass and using it to examine the cellular structure of plants.

1. Examine a hand-held magnifying glass. What parts does it have? What is their purpose?

A hand magnifying glass consists of a handle and a magnifying glass, convex on both sides and inserted into a frame. When working, the magnifying glass is taken by the handle and brought closer to the object at a distance at which the image of the object through the magnifying glass is most clear.

2. Examine with the naked eye the pulp of a semi-ripe tomato, watermelon, or apple. What is characteristic of their structure?

The pulp of the fruit is loose and consists of tiny grains. These are cells.

It is clearly visible that the pulp of the tomato fruit has a granular structure. The apple's pulp is slightly juicy, and the cells are small and tightly packed together. The pulp of a watermelon consists of many cells filled with juice, which are located either closer or further away.

3. Examine pieces of fruit pulp under a magnifying glass. Draw what you see in your notebook and sign the drawings. What shape do the fruit pulp cells have?

Even with the naked eye, or even better under a magnifying glass, you can see that the flesh of a ripe watermelon consists of very small grains, or grains. These are cells - the smallest “building blocks” that make up the bodies of all living organisms. Also, the pulp of a tomato fruit under a magnifying glass consists of cells similar to rounded grains.

Laboratory work No. 2. The structure of a microscope and methods of working with it.

1. Examine the microscope. Find the tube, eyepiece, lens, tripod with stage, mirror, screws. Find out what each part means. Determine how many times the microscope magnifies the image of the object.

Tube is a tube that contains the eyepieces of a microscope. An eyepiece is an element of the optical system facing the observer’s eye, a part of the microscope designed to view the image formed by the mirror. The lens is designed to construct an enlarged image with accurate reproduction of the shape and color of the object of study. A tripod holds the tube with an eyepiece and objective at a certain distance from the stage on which the material being examined is placed. The mirror, which is located under the object stage, serves to supply a beam of light under the object in question, i.e., it improves the illumination of the object. Microscope screws are mechanisms for adjusting the most effective image on the eyepiece.

2. Familiarize yourself with the rules for using a microscope.

When working with a microscope, the following rules must be observed:

1. You should work with a microscope while sitting;

2. Inspect the microscope, wipe the lenses, eyepiece, mirror from dust with a soft cloth;

3. Place the microscope in front of you, slightly to the left, 2-3 cm from the edge of the table. Do not move it during operation;

4. Open the aperture completely;

5. Always start working with a microscope at low magnification;

6. Lower the lens to the working position, i.e. at a distance of 1 cm from the slide;

7. Set the illumination in the field of view of the microscope using a mirror. Looking into the eyepiece with one eye and using a mirror with a concave side, direct the light from the window into the lens, and then illuminate the field of view as much as possible and evenly;

8. Place the microspecimen on the stage so that the object being studied is under the lens. Looking from the side, lower the lens using the macroscrew until the distance between the lower lens of the lens and the microspecimen becomes 4-5 mm;

9. Look into the eyepiece with one eye and rotate the coarse aiming screw towards yourself, smoothly raising the lens to a position at which the image of the object can be clearly seen. You cannot look into the eyepiece and lower the lens. The front lens may crush the cover glass and cause scratches;

10. Moving the specimen by hand, find the desired location and place it in the center of the microscope’s field of view;

11. After finishing work with high magnification, set the magnification to low, raise the lens, remove the specimen from the work table, wipe all parts of the microscope with a clean napkin, cover it with a plastic bag and put it in a cabinet.

3. Practice the sequence of actions when working with a microscope.

1. Place the microscope with the tripod facing you at a distance of 5-10 cm from the edge of the table. Use a mirror to shine light into the opening of the stage.

2. Place the prepared preparation on the stage and secure the slide with clamps.

3. Using the screw, smoothly lower the tube so that the lower edge of the lens is at a distance of 1-2 mm from the specimen.

4. Look into the eyepiece with one eye without closing or squinting the other. While looking through the eyepiece, use the screws to slowly lift the tube until a clear image of the object appears.

5. After use, put the microscope in its case.

Question 1. What magnifying devices do you know?

Hand magnifier and tripod magnifier, microscope.

Question 2. What is a magnifying glass and what magnification does it provide?

A magnifying glass is the simplest magnifying device. A hand magnifying glass consists of a handle and a magnifying glass, convex on both sides and inserted into a frame. It magnifies objects 2-20 times.

A tripod magnifying glass magnifies objects 10-25 times. Two magnifying glasses are inserted into its frame, mounted on a stand - a tripod. A stage with a hole and a mirror is attached to the tripod.

Question 3. How does a microscope work?

Magnifying glasses (lenses) are inserted into the viewing tube, or tube, of this light microscope. At the upper end of the tube there is an eyepiece through which various objects are viewed. It consists of a frame and two magnifying glasses. At the lower end of the tube is placed a lens consisting of a frame and several magnifying glasses. The tube is attached to a tripod. An object table is also attached to the tripod, in the center of which there is a hole and a mirror under it. Using a light microscope, you can see an image of an object illuminated by this mirror.

Question 4. How to find out what magnification a microscope gives?

To find out how much the image is magnified when using a microscope, you need to multiply the number indicated on the eyepiece by the number indicated on the objective lens you are using. For example, if the eyepiece provides 10x magnification and the objective provides 20x magnification, then the total magnification is 10 x 20 = 200x.

Think

Why can't we study opaque objects using a light microscope?

The main principle of operation of a light microscope is that light rays pass through a transparent or translucent object (object of study) placed on the stage and hit the lens system of the objective and eyepiece. And light does not pass through opaque objects, and therefore we will not see an image.

Quests

Learn the rules of working with a microscope (see above).

Using additional sources of information, find out what details of the structure of living organisms can be seen with the most modern microscopes.

The light microscope made it possible to examine the structure of cells and tissues of living organisms. And now, it has been replaced by modern electron microscopes, which allow us to examine molecules and electrons. And an electron scanning microscope allows you to obtain images with a resolution measured in nanometers (10-9). It is possible to obtain data concerning the structure of the molecular and electronic composition of the surface layer of the surface under study.

Municipal preschool educational institution, kindergarten of a general developmental type with priority implementation of activities for the physical development of children “Forget-Me-Not” No. 133

Summary of direct educational activities to get acquainted with the world around us in the middle group Topic: “Journey to the world of transparent and opaque.”

Prepared by:

Prygunova Natalya Evgenievna,

middle group teacher

Komsomolsk-on-Amur

Summary of direct educational activities to get acquainted with the world around us in the middle group Topic: “Journey to the world of transparent and opaque.”

Target: identify the properties and qualities of transparent and opaque objects.

Software tasks:

1. To develop in children methods of sensory examination that make it possible to highlight transparency in the material - opacity as its quality.

2. Develop curiosity and interest in learning about surrounding objects.

3. Contribute to the enrichment of vocabulary through words and expressions: transparent, opaque, glass, plastic, fragile, sounding, voiced, deaf, look through (through).

4. Foster a caring attitude towards objects created by human hands.

Teaching methods: practical, game, verbal.

Materials and equipment for the lesson: 2 glasses (transparent and opaque), small toys for playing (4-6 pieces), glass and plastic transparent objects (glasses, vases, jars, glasses, flasks, bottles...), opaque objects (box, vase, napkin, glass , leaf...), toy - Pinocchio,

GCD move:

Pinocchio comes to the group of children, greets them, and offers to play an interesting game. Pinocchio: The game is called “Riddles and Guessing”. I have two glasses, I will ask you riddles by putting a toy in the glass, and you must guess what I hid in the glasses. Pinocchio: Why did you guess what is in this glass? (Transparent). Why didn’t you guess what was in this glass? (Opaque). Educator: What a cunning Pinocchio, he has 2 glasses, an object is visible through this glass, because it is ... (transparent), but through this glass it is not visible, because it is ... (opaque). Guys, and you, Pinocchio, want to know more about transparent and opaque objects, about what they are? I propose to go on a journey into the magical world of transparent and opaque objects. If we fly by plane, we’ll get there faster. Do you agree? Close your eyes, spread your wings, fly above the clouds, drop lower and lower, and land. So we arrived.

Educator: Guys, look, we are greeted by various objects (there are transparent glass and plastic objects on the table).

Name what objects you see (children list).

Take one of any objects and look through it at each other.

What can you say about these objects, what are they? (transparent)

Why? (because you can see through it)

Buratino also has two glasses (glass and plastic), he also looks through them.

Educator: Look, Pinocchio has two glasses. Take the same glasses as Pinocchio's and stand near the tables.

"Inspection of glasses"

Educator: Pick up a glass like Pinocchio’s (glass). What material is it made of? Place it on your cheek and tell me what it is like? (Cold). Press the glass, what is it like? (Solid).

Then the children examine the plastic glass in the same way.

Educator: Which glass is heavier? Educator: How are the glasses different? (one glass is glass, it is hard, heavy, the other glass is plastic, it is light, soft, bendable). Educator: Pinocchio, how do you think these two glasses are similar, what do they have in common? Buratino replies that the glasses are nothing alike. Educator: Guys, what do you think? (Both glasses are transparent, both belong to tableware). Educator: I want to introduce you to one more property of glass objects. Invites children to take sticks and knock on glass objects, then on a plastic glass. He asks what the children hear. Conclusion: clear-sounding glass; plastic makes a dull sound. Pinocchio drops a plastic glass on the floor. Educator: What happened to the plastic cup? Why didn't he crash? We also have a second glass. -What is he like? Pinocchio, what do you think will happen to a glass glass if it is dropped on the floor? Buratino believes that nothing will happen. The teacher asks the children a question. (It may break, it is glass and fragile). Educator: Glass objects are fragile and easy to break, so they must be handled with care and precision. The teacher invites the children to guess the riddle.

Sounding, transparent

I'm not afraid of water

If you hit me, I’ll break.

What glass are we talking about in this riddle? Why do you think so?

Educator: Pinocchio, now do you understand how to handle glass objects? And we have a lot of them in our group.

Educator: Guys, today we talked about such a property of objects as transparency. Do you think we need transparent objects? Which? Why? (children's answers)

Pinocchio: And I have a surprise for you (invites the children to sit at the table). - I hid the object under the table. Look through the table cover and find out what it is? Children: Can't see anything. Educator: What can you say about the table, is it transparent or opaque? Why? Find opaque objects in the group and bring them to the table. Children find opaque objects in the group, bring them, and explain their choice.

It's time for us to return to kindergarten. Close your eyes, spread your wings, fly above the clouds, drop lower and lower, and land. So we returned to kindergarten.

Educator: Did you enjoy your trip to the land of transparent and opaque objects? What interesting things did you learn? What surprised you today? What subjects would you like to learn more about?