Introduction…………………………………………………………………………………………….4
Main part……………………………………………………………………………….…..6
1. Soap bubble and its structure. ………………………………………………………..…6
2. Durability of soap bubbles. How Bubbles Burst………………………………………………..……………………………………………...7
3. Soap bubble rainbow……………………………………………………………………...7
4. Freezing of bubbles……………………………………………………………………………...8
Experimental part.
Making soap bubbles……………………………………………………………....11
Cooking recipe…………………………………………………………………..….12
Conclusion…………………………………………………………………………………...…14
Bibliographic list……………………………………………………………………....15
Application
Introduction.
I love to blow bubbles. I like to admire their round shape and iridescent surface with different colors. I blew bubbles out of a straw and watched the round rainbow balls fly.
I always wanted to get a bubble that didn’t look like a ball, so that its shape resembled the shape of a cube or the head of some animal. But, unfortunately, my soap bubbles always turned out only round.
Why are soap bubbles round like balloons? Maybe if you use a wire frame in the shape of a cube or a triangle to inflate the bubble, you get a bubble of a different shape? Consider the problem of obtaining round soap bubbles.
So,an object myresearch: bubble.
Subject of study: shape and composition of soap bubbles.
I put forward the followinghypothesis: using wire frames of different geometric shapes, it is possible to make non-circular soap bubbles.
Purpose of my research: identify the properties and shape of soap bubbles. I will achieve my goal by solvingadachi:
collect information about the preparation, properties and shape of soap bubbles;
prepare a solution of soap bubbles at home;
make soap bubbles
analyze the theoretical and practical results of obtaining soap bubbles, their properties and shape.
Research stages:
to make wire frames of different geometric shapes;
prepare a solution for soap bubbles and buy a ready-made solution in a store for comparison;
try to blow geometric bubbles of different shapes;
collect information about the shape and properties of soap bubbles (ask parents, read in a book, find on the Internet);
determine which solution for making bubbles is the best;
compare the theoretical and practical results of making soap bubbles;
Methods and techniques: observation, experiment, analysis.
Applied significance my research work lies in the fact that the results of my research can be applied in the lessons of the world around us and in scientific circles. The beauty of soap bubbles suggests one of the directions of their application: in decoration, festive events, various kinds of celebrations. For such an application, special machines have been invented to generate a constant stream of soap bubbles; this flow is picked up by powerfuland lit up in different colors.
Some artists use soap bubbles as the main element for their performances; in this case, they demonstrate huge bubbles - more than a meter in diameter.
Main part.
Soap bubble and its structure.
I turned to the Internet for information. Having studied the topic of interest to me, I analyzed the information and found out the following.
Soap bubble- thin multilayer film water filled with air iridescent . Soap bubbles usually last only a few seconds and burst when touched or spontaneously. 5 .
The shell of a soap bubble consists of a thin layer of water, which determines the opacity of the soap bubble and its stability. In a glass, water has only one free surface and, accordingly, only one layer of soap molecules can form on it. A free film has two surfaces, which means that two layers of elongated soap molecules can form on it. It is from such a water film reinforced with soap molecules that a soap bubble consists 3 .
Based on the above, I came to the conclusion that in order to blow a soap bubble, it is necessary to place a bubble frame in a jar of soap solution. At this time, a soap film is formed on the frame, which consists of soap and water. There is air inside the bubble. We blow on the film in the frame, the film closes into a ball, and the air is inside.Thus A soap bubble is made up of water, soap and air.
Bubble durability. How bubbles burst.
Watching ordinary bubbles, I noticed that they are short-lived and burst immediately. But soap bubbles live much longer. Above, I have already emphasized that the film of a soap bubble consists of soap and water. A thin strip of water is placed between two layers of soap. At the same time, the bubble film is very thin, thinner than our hair. Soap retains water longer. And while the bubble is wet, it does not burst.
The bubble exists because the surface of any liquid (in this case water) has some surface tension that makes the surface behave like something else. .
Some scientists preserved soap bubbles in every possible way, storing them for several days and even months, but no matter how long the life of a soap bubble is, sooner or later it will still burst.
Have you thought about how this happens? It seems to us that this is an instant action. There is still a soap bubble, but it just evaporated in the air. But did you know that action is directed, not chaotic? Scientists have calculated that a soap bubble bursts in one thousandth of a second, therefore, in order to see this miracle, they needed a camera capable of shooting up to 5000 frames per second. On the slow motion film, it was clear that as soon as the integrity of the soap bubble was broken, its shell gradually began to collapse from the point of damage and further along the entire circumference. In confirmation of their experiments, scientists provided photos and videos, where the process of bursting a soap bubble is clearly visible.
3. "Rainbow" of a soap bubble
The bubble film consists of several layers. When light passes through these layers, it changes (refracts), shimmers. We observe a similar phenomenon when we look at a rainbow after rain.
RUSSIAN FEDERATION
administration of the municipality - Shilovsky municipal district of the Ryazan region
Municipal budgetary educational institution
Shilovskaya Secondary School No. 3
municipal formation - Shilovsky municipal district of the Ryazan region
Legal address: 391500 r. Shilovo village, st. Isaeva, 34 phone/fax 8(49136)21847,
email: shilovo - school 3@ yandex . en TIN/KPP 6225004968/622501001 PSRN 1026200850873
Scientific and practical conference
Section: the world around
Why are soap bubbles round?
The work was done by a student of grade 1B: Kucherova Veronika
Scientific adviser: Geraskova N.A.
Shilovo village, 2018
The reason for this is the surface tension forces of the liquid. They occur between water particles. Particles of water or other liquid, being attracted to each other, tend to get closer. Each particle on the surface is attracted by the rest of the particles inside the liquid, and therefore rush towards each other (see Fig. 3).
It is due to surface tension that the spherical shape of the bubble is obtained. This shape can be significantly distorted by air currents and the bubble inflation process itself. However, if the bubble is left to float freely in the air, its shape will very soon become close to spherical.
When light passes through the thin film of the bubble, part of it is reflected from the outer surface, while another part penetrates the film and is reflected from the inner surface (see Fig. 4). The color of the radiation observed in the reflection is determined by the interference of these two reflections.
In the end, the bubble wall becomes thinner than the wavelength of visible light, all the reflected waves of visible light add up in antiphase, and we stop seeing the reflection at all (against a dark background, this part of the bubble looks like a “black spot”). When this happens, the wall thickness of the soap bubble is less than 25 nanometers, and the bubble is likely to burst soon.
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How long do soap bubbles live?
Previously, there was an opinion that the "life" of a soap bubble is fleeting. However, this idea was dispelled by the English inventor James Dewar. He conducted an experiment and tried to preserve the bubbles in special sealed containers, reliably protecting them from external influences. It turned out that soap bubbles can last for a month or even more.
For one of the physics teachers in the US state of Indiana, a soap bubble placed in a glass jar “lived” for 340 days. There is evidence that soap balloons are stored under a glass cap for many years.
How do bubbles burst?
Some scientists preserved soap bubbles in every possible way, storing them for several days and even months, but no matter how long the life of a soap bubble is, sooner or later it will still burst. Have you thought about how this happens? At first, the lower part of the bubble will thicken, and the central upper part will thin out. This is clearly seen from the fluid flows that change the spotty color of the bubble. At some point, the bubble will burst. It seems to us that this is an instantaneous action, but in fact we see only the final stage - the bubble turns into a set of drops located along the perimeter. As a rule, the center of destruction, destruction is in the upper, thinnest place of the film.
round bubbles
We all admire bubbles, especially soap bubbles - their perfectly round shape and iridescent surface with different colors. Boys, an English physicist, was so intrigued by soap bubbles that he wrote a 200-page book, Bubbles. Their color and the forces that give them shape. Boys called soap bubbles an excellent experimental object and pointed out that the forces that give shape to a bubble are present in all liquids.
These forces are omnipresent. Tea brewing is indispensable without them, without them it is impossible to close the current tap in the kitchen, they are remembered when diving into the water. In general, any liquid has this power.
What causes water droplets to cluster together?
Imagine that you are filling a balloon with water. The more water you pour into it, the more the rubber shell of the ball stretches. Eventually, it will stop stretching and burst. Now imagine a drop of water. Water collects at the tip of the pipette in the form of a growing drop. The drop gets bigger and bigger. Finally, it reaches a certain critical size and breaks away from the pipette tip.
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Boys asked himself, “Why does water collect at the tip of a pipette in the form of a drop at all?” The impression is that the water flows into a small elastic bag, like a balloon. This bag comes off the pipette when it overflows with water. Naturally, there is no elastic bag around the drop. But something must hold the drop in its classical form. There must be some kind of invisible shell, some kind of something.
Surface tension
This something - a property of water and any other liquid - is called surface tension. Let's take water. Water molecules under its surface are interconnected by powerful forces of intermolecular interaction. Molecules located in the surface layer experience an attractive force only from the underlying and neighboring molecules. That is, surface water molecules are attracted inward and sideways. It is this interaction of forces that creates a film effect, or surface tension, on the surface of the water.
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Thus, surface tension can be considered as a kind of "shell" of water. This sheath causes the drop to hang from the end of the faucet. When the drop becomes too large, the shell does not withstand and breaks. Boys emphasized that different liquids have shells with different strengths. Alcohol has a lower surface tension, so it forms smaller droplets than water. But mercury, which runs around the floor in small balls when the thermometer breaks, has a surface tension six times greater than that of water.
What keeps the bubble from bursting?
The force of surface tension prevents the bubble from bursting. When you dip the frame into the soap solution and then take it out, you see a thin iridescent film that closes the gap of the frame. Blow on the frame. A bubble will begin to bulge out of it. The soap film stretches like an elastic shell. Blow some more. The soap film will close around the air, and the soap bubble will go on an independent journey, shimmering with all the colors of the rainbow.
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The shell of a soap bubble has elastic properties, so the air inside the bubble is under pressure, like the air inside the chamber of a soccer ball. The value inside the bubble pressure depends on the curvature of the bubble wall. The greater the curvature and the smaller the bubble, the greater the pressure. Boys experimentally proved that the air escaping from a bursting soap bubble can extinguish the flame of a candle.
But why is the bubble still round?
The answer is that surface tension tends to keep the soap bubble as compact as possible. The most compact shape in nature is a sphere (not a cube, for example). With a spherical shape, the air inside the bubble evenly presses on all parts of its inner wall (at least until the bubble bursts).
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However, the same Boys noted that by applying an external force, it is possible to make a bubble of a non-spherical shape. If a soap film is stretched between two rings and pulled to break, a cylindrical soap bubble is formed. The larger the size of such a cylindrical bubble, the lower its strength. In the end, a constriction appears in the middle of such a bubble, and it divides into two ordinary round bubbles.
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- Why are soap bubbles round?
- Project author: Daria Viktorovna Kadachigova, student of the 4th "B" class,
- MBOU "Secondary School No. 2 named after. A. I. Isaeva»
- Head: Garbuzova Irina Igorevna, primary school teacher
- bubble
- Subject of study:
- form and composition
- soap bubbles
- Research hypothesis:
- if you use wire frames of different geometric shapes, you can get non-circular soap bubbles.
- Purpose of the study:
- identify the properties and shape of soap bubbles.
- Tasks:
- collect information about the shape, properties
- and preparation of soap bubbles;
- 2) prepare a solution for soap bubbles
- at home;
- 3) make soap bubbles;
- 4) analyze the theoretical and practical results of obtaining soap bubbles, their properties and shape.
- Search.
- observation.
- Comparison.
- Modeling.
- Analysis and generalization.
- Research methods:
- Organizational (make wire frames of different geometric shapes);
- Analytical ( collect information about the shape and properties of soap bubbles; ask your parents, read in a book, find on the Internet; determine which solution for making bubbles is the best);
- Practical (prepare a solution for soap bubbles and buy a ready-made solution in a store for comparison; try to blow geometric bubbles of different shapes);
- Final (compare the theoretical and practical result of manufacturing
- soap bubbles.)
- "The soap bubble is perhaps the most delightful and most exquisite phenomenon of nature."
- Mark Twain
- BOYS Charles Vernon
- Surface tension keeps the bubble from bursting.
- The forces of surface tension tend to give the soap bubble the shape of a ball.
- Secrets of the production of soap bubbles.
- The water must be soft. The easiest way to soften water is to boil it well and let it stand. To prepare the solution, it is better to take warm water, the detergent dissolves faster in it.
- If soap is used as a detergent, then it is better to take household domestic production.
- The bubble lives as long as it is wet. In order for the soap film not to dry out as long as possible, glycerin is added to the solution. Glycerin can be replaced with an aqueous solution of sugar with gelatin.
- It is better to blow bubbles in a cool place.
- The surface of the instruments from which the bubbles are blown should be rough to reduce the sliding of the soap solution on it.
- 3rd place
- 1 place
- 2nd place
- When inflating a soap bubble, it can only be round in shape, since surface tension forces give the soap bubble the shape of a ball.
- 2. It is best to use laundry soap for making soap bubbles at home, as it does not contain additives and the solution is the purest, which affects the quality of the soap bubble.
