Chemical experiments with metals. Entertaining chemistry lesson for elementary school "miracles, and only"
Municipal budgetary educational institution
"Secondary school No. 35", Bryansk
Entertaining experiments in chemistry
Developed
chemistry teacher of the highest category
Velicheva Tamara Alexandrovna
When conducting experiments, it is necessary to observe safety precautions, skillfully handle substances, utensils and appliances. These experiments do not require complex equipment and expensive reagents, and their effect on the audience is enormous.
"Golden" nail.
Pour 10-15 ml of copper sulfate solution into a test tube and add a few drops of sulfuric acid. An iron nail is dipped into the solution for 5-10 seconds. A red coating of metallic copper appears on the surface of the nail. To give shine, the nail is rubbed with filter paper.
Pharaoh snakes.
Crushed dry fuel is placed on the asbestos mesh. Norsulfazole tablets are placed around the top of the hill at the same distance from each other. During the demonstration of the experiment, the top of the hill is set on fire with a match. During the experiment, it is monitored that three independent “snakes” are formed from three norsulfazole tablets. To prevent sticking of the reaction products into one "snake", it is necessary to correct the resulting "snakes" with a splinter.
Bank explosion.
For the experiment, they take a can of coffee (without a lid) with a capacity of 600-800 ml and punch a small hole in the bottom. The jar is placed on the table upside down and, having closed the hole with a damp piece of paper, a gas outlet tube from Kiryushkin's device for filling with hydrogen is brought from below ( the jar is filled with hydrogen for 30 seconds). Then the tube is removed, and the gas is ignited with a long splinter through the hole in the bottom of the jar. At first, the gas burns quietly, and then the buzz begins and an explosion occurs. The jar bounces high up and flames burst out. The explosion occurs because an explosive mixture has formed in the bank.
"Dance of the Butterflies".
For experience, “butterflies” are made in advance. The wings are cut out of tissue paper and glued to the body (fragments of a match or toothpick) for greater stability in flight.
A wide-mouthed jar is prepared, hermetically sealed with a stopper, into which a funnel is inserted. The diameter of the funnel at the top should be no more than 10 cm. Acetic acid CH 3 COOH is poured into the jar so much that the lower end of the funnel does not reach the surface of the acid by about 1 cm. Then, several tablets of sodium bicarbonate (NaHCO 3) are thrown through a funnel into a jar of acid, and the "butterflies" are placed in a funnel. They begin to "dance" in the air.
"Butterflies" are kept in the air by a jet of carbon dioxide formed as a result of a chemical reaction between sodium bicarbonate and acetic acid:
NaHCO 3 + CH 3 COOH \u003d CH 3 COONa + CO 2 + H 2 O
Lead coat.
A human figure is cut out of a thin zinc plate, cleaned well and lowered into a glass with a solution of tin chloride SnCl 2 . A reaction begins, as a result of which the more active zinc displaces the less active tin from the solution:
Zn + SnCl 2 = ZnCl 2 + Sn
The zinc figurine begins to be covered with shiny needles.
Fire cloud.
Flour is sifted through a frequent sieve and flour dust is collected, which settles far along the sides of the sieve. It dries well. Then two full teaspoons of flour dust are introduced into a glass tube, closer to the middle, and shake it a little along the length of the tube by 20-25 cm.
Then the dust is strongly blown over the flame of an alcohol lamp placed on a demonstration table (the distance between the end of the tube and the alcohol lamp should be about one meter).
A "fiery" cloud is formed.
"Star Rain.
Take three teaspoons of iron powder, the same amount of pounded charcoal. All this is mixed and poured into a crucible. It is fixed in a tripod and heated on a spirit lamp. Soon the "starry" rain begins.
These incandescent particles are ejected from the crucible by carbon dioxide formed during the combustion of coal.
Changing the color of flowers.
In a large battery glass, a mixture is prepared from three parts of diethyl ether C 2 H 5 ─ O ─ C 2 H 5 and one part (by volume) of a strong solution of ammonia NH 3 ( there should be no fire nearby). Ether is added in order to facilitate the penetration of ammonia into the cells of the flower petal.
Individual flowers or a bunch of flowers are dipped into an ether-ammonia solution. This will change their color. Red, blue and purple flowers will turn green, white (white rose, chamomile) will turn dark, yellow will retain their natural color. The changed color is preserved by flowers for several hours, after which it turns into natural.
This is due to the fact that the color of fresh flower petals is caused by natural organic dyes, which have indicator properties and change their color in an alkaline (ammonia) environment.
List of used literature:
Shulgin G.B. This fascinating chemistry. M. Chemistry, 1984.
Shkurko M.I. Entertaining experiments in chemistry. Minsk. Narodnaya Asveta, 1968.
Aleksinsky V.N. Entertaining experiments in chemistry. A guide for the teacher. M. Education, 1980.
My personal experience of teaching chemistry has shown that such a science as chemistry is very difficult to study without any initial knowledge and practice. Schoolchildren very often run this subject. I personally observed how a student of the 8th grade at the word "chemistry" began to frown, as if he had eaten a lemon.
Later it turned out that because of dislike and misunderstanding of the subject, he skipped school in secret from his parents. Of course, the school curriculum is designed in such a way that the teacher must give a lot of theory at the first chemistry lessons. Practice, as it were, fades into the background precisely at the moment when the student cannot yet independently realize whether he needs this subject in the future. This is primarily due to the laboratory equipment of schools. In big cities, things are better now with reagents and instruments. As for the province, as well as 10 years ago, and at present, many schools do not have the opportunity to conduct laboratory classes. But the process of studying and fascination with chemistry, as well as with other natural sciences, usually begins with experiments. And it is no coincidence. Many famous chemists, such as Lomonosov, Mendeleev, Paracelsus, Robert Boyle, Pierre Curie and Maria Sklodowska-Curie (schoolchildren also study all these researchers in physics classes) have already started experimenting since childhood. The great discoveries of these great people were made in home chemical laboratories, since chemistry classes at institutes were available only to wealthy people.
And, of course, the most important thing is to interest the child and convey to him that chemistry surrounds us everywhere, so the process of studying it can be very exciting. This is where home chemistry experiments come in handy. Observing such experiments, one can further look for an explanation of why things happen this way and not otherwise. And when a young researcher comes across such concepts at school lessons, the teacher’s explanations will be more understandable to him, since he will already have his own experience in conducting home chemical experiments and the knowledge gained.
It is very important to start science studies with the usual observations and real life examples that you think will be the best for your child. Here is some of them. Water is a chemical substance consisting of two elements, as well as gases dissolved in it. Man also contains water. We know that where there is no water, there is no life. A person can live without food for about a month, and without water - only a few days.
River sand is nothing but silicon oxide, and also the main raw material for glass production.
A person himself does not suspect it and carries out chemical reactions every second. The air we breathe is a mixture of gases - chemicals. In the process of exhalation, another complex substance is released - carbon dioxide. We can say that we ourselves are a chemical laboratory. You can explain to the child that washing hands with soap is also a chemical process of water and soap.
An older child who, for example, has already begun to study chemistry at school, can be explained that almost all elements of the periodic system of D. I. Mendeleev can be found in the human body. In a living organism, not only all chemical elements are present, but each of them performs some biological function.
Chemistry is also medicines, without which at present many people cannot live even a day.
Plants also contain the chemical chlorophyll, which gives the leaf its green color.
Cooking is a complex chemical process. Here you can give an example of how the dough rises when yeast is added.
One of the options for getting a child interested in chemistry is to take an individual outstanding researcher and read the story of his life or watch an educational film about him (films about D.I. Mendeleev, Paracelsus, M.V. Lomonosov, Butlerov are now available).
Many believe that real chemistry is harmful substances, it is dangerous to experiment with them, especially at home. There are many very exciting experiences that you can do with your child without harming your health. And these home chemical experiments will be no less exciting and instructive than those that come with explosions, pungent odors and puffs of smoke.
Some parents are also afraid to conduct chemical experiments at home because of their complexity or the lack of the necessary equipment and reagents. It turns out that you can get by with improvised means and those substances that every housewife has in the kitchen. You can buy them at your nearest household store or pharmacy. Test tubes for home chemical experiments can be replaced with pill bottles. For storage of reagents, you can use glass jars, for example, from baby food or mayonnaise.
It is worth remembering that the dishes with reagents must have a label with the inscription and be tightly closed. Sometimes the tubes need to be heated. In order not to hold it in your hands when heated and not get burned, you can build such a device using a clothespin or a piece of wire.
It is also necessary to allocate several steel and wooden spoons for mixing.
You can make a stand for holding test tubes yourself by drilling through holes in the bar.
To filter the resulting substances, you will need a paper filter. It is very easy to make it according to the diagram given here.
For children who do not yet go to school or are studying in elementary grades, setting up home chemical experiments with their parents will be a kind of game. Most likely, such a young researcher will not yet be able to explain some individual laws and reactions. However, it is possible that just such an empirical way of discovering the surrounding world, nature, man, plants through experiments will lay the foundation for the study of natural sciences in the future. You can even arrange original competitions in the family - who will have the most successful experience and then demonstrate them at family holidays.
Regardless of the age of the child and his ability to read and write, I advise you to have a laboratory journal in which you can record experiments or sketch. A real chemist must write down a work plan, a list of reagents, sketches of instruments and describes the progress of work.
When you and your child just begin to study this science of substances and conduct home chemical experiments, the first thing to remember is safety.
To do this, follow the following safety rules:
2. It is better to allocate a separate table for conducting chemical experiments at home. If you do not have a separate table at home, then it is better to conduct experiments on a steel or iron tray or pallet.
3. It is necessary to get thin and thick gloves (they are sold in a pharmacy or hardware store).
4. For chemical experiments, it is best to buy a lab coat, but you can also use a thick apron instead of a dressing gown.
5. Laboratory glassware should not be used for food.
6. In home chemical experiments, there should be no cruelty to animals and violation of the ecological system. Acidic chemical waste should be neutralized with soda, and alkaline with acetic acid.
7. If you want to check the smell of a gas, liquid or reagent, never bring the vessel directly to your face, but, holding it at a certain distance, direct, waving your hand, the air above the vessel towards you and at the same time smell the air.
8. Always use small amounts of reagents in home experiments. Avoid leaving reagents in a container without an appropriate inscription (label) on the bottle, from which it should be clear what is in the bottle.
The study of chemistry should begin with simple chemical experiments at home, allowing the child to master the basic concepts. A series of experiments 1-3 allow you to get acquainted with the basic aggregate states of substances and the properties of water. To begin with, you can show a preschooler how sugar and salt dissolve in water, accompanying this with an explanation that water is a universal solvent and is a liquid. Sugar or salt are solids that dissolve in liquids.
Experience number 1 "Because - without water and neither here nor there"
Water is a liquid chemical substance composed of two elements as well as gases dissolved in it. Man also contains water. We know that where there is no water, there is no life. A person can live without food for about a month, and without water - only a few days.
Reagents and equipment: 2 test tubes, soda, citric acid, water
Experiment: Take two test tubes. Pour in equal amounts of soda and citric acid. Then pour water into one of the test tubes, and not into the other. In a test tube in which water was poured, carbon dioxide began to be released. In a test tube without water - nothing has changed
Discussion: This experiment explains the fact that many reactions and processes in living organisms are impossible without water, and water also accelerates many chemical reactions. Schoolchildren can be explained that an exchange reaction has taken place, as a result of which carbon dioxide has been released.
Experience number 2 "What is dissolved in tap water"
Reagents and equipment: clear glass, tap water
Experiment: Pour tap water into a transparent glass and put it in a warm place for an hour. After an hour, you will see settled bubbles on the walls of the glass.
Discussion: Bubbles are nothing but gases dissolved in water. Gases dissolve better in cold water. As soon as the water becomes warm, the gases cease to dissolve and settle on the walls. A similar home chemical experiment also makes it possible to acquaint the child with the gaseous state of matter.
Experience No. 3 “What is dissolved in mineral water or water is a universal solvent”
Reagents and equipment: test tube, mineral water, candle, magnifying glass
Experiment: Pour mineral water into a test tube and slowly evaporate it over a candle flame (the experiment can be done on the stove in a saucepan, but the crystals will be less visible). As the water evaporates, small crystals will remain on the walls of the test tube, all of them of different shapes.
Discussion: Crystals are salts dissolved in mineral water. They have a different shape and size, since each crystal has its own chemical formula. With a child who has already begun to study chemistry at school, you can read the label on mineral water, which indicates its composition and write the formulas of the compounds contained in mineral water.
Experiment No. 4 "Filtration of water mixed with sand"
Reagents and equipment: 2 test tubes, funnel, paper filter, water, river sand
Experiment: Pour water into a test tube and dip a little river sand into it, mix. Then, according to the scheme described above, make a filter out of paper. Insert a dry, clean test tube into a rack. Slowly pour the sand/water mixture through a filter paper funnel. River sand will remain on the filter, and you will get clean water in a tripod tube.
Discussion: Chemical experience allows us to show that there are substances that do not dissolve in water, for example, river sand. The experience also introduces one of the methods of cleaning mixtures of substances from impurities. Here you can introduce the concepts of pure substances and mixtures, which are given in the 8th grade chemistry textbook. In this case, the mixture is sand with water, the pure substance is the filtrate, and river sand is the sediment.
The filtration process (described in Grade 8) is used here to separate a mixture of water and sand. To diversify the study of this process, you can delve a little into the history of drinking water purification.
Filtration processes were used as early as the 8th and 7th centuries BC. in the state of Urartu (now it is the territory of Armenia) for the purification of drinking water. Its inhabitants carried out the construction of a water supply system with the use of filters. Thick cloth and charcoal were used as filters. Similar systems of intertwined drainpipes, clay canals, equipped with filters were also on the territory of the ancient Nile among the ancient Egyptians, Greeks and Romans. Water was passed through such a filter repeatedly through such a filter several times, eventually many times, ultimately achieving the best water quality.
One of the most interesting experiments is growing crystals. The experience is very clear and gives an idea of many chemical and physical concepts.
Experience number 5 "Grow sugar crystals"
Reagents and equipment: two glasses of water; sugar - five glasses; wooden skewers; thin paper; pan; transparent cups; food coloring (the proportions of sugar and water can be reduced).
Experiment: The experiment should begin with the preparation of sugar syrup. We take a pan, pour 2 cups of water and 2.5 cups of sugar into it. We put on medium heat and, stirring, dissolve all the sugar. Pour the remaining 2.5 cups of sugar into the resulting syrup and cook until completely dissolved.
Now let's prepare the embryos of crystals - sticks. Scatter a small amount of sugar on a piece of paper, then dip the stick in the resulting syrup, and roll it in sugar.
We take the pieces of paper and pierce a hole in the middle with a skewer so that the piece of paper fits snugly against the skewer.
Then we pour the hot syrup into transparent glasses (it is important that the glasses are transparent - this way the process of crystal ripening will be more exciting and visual). The syrup must be hot or the crystals will not grow.
You can make colored sugar crystals. To do this, add a little food coloring to the resulting hot syrup and stir it.
The crystals will grow in different ways, some quickly and some may take longer. At the end of the experiment, the child can eat the resulting lollipops if he is not allergic to sweets.
If you do not have wooden skewers, then you can experiment with ordinary threads.
Discussion: A crystal is a solid state of matter. It has a certain shape and a certain number of faces due to the arrangement of its atoms. Crystalline substances are substances whose atoms are arranged regularly, so that they form a regular three-dimensional lattice, called a crystal. Crystals of a number of chemical elements and their compounds have remarkable mechanical, electrical, magnetic and optical properties. For example, diamond is a natural crystal and the hardest and rarest mineral. Due to its exceptional hardness, diamond plays a huge role in technology. Diamond saws cut stones. There are three ways to form crystals: crystallization from a melt, from a solution, and from a gas phase. An example of crystallization from a melt is the formation of ice from water (after all, water is molten ice). An example of crystallization from solution in nature is the precipitation of hundreds of millions of tons of salt from sea water. In this case, when growing crystals at home, we are dealing with the most common methods of artificial growing - crystallization from a solution. Sugar crystals grow from a saturated solution by slowly evaporating the solvent - water, or by slowly lowering the temperature.
The following experience allows you to get at home one of the most useful crystalline products for humans - crystalline iodine. Before conducting the experiment, I advise you to watch with your child a short film “The life of wonderful ideas. Smart iodine. The film gives an idea of the benefits of iodine and the unusual story of its discovery, which will be remembered by the young researcher for a long time. And it is interesting because the discoverer of iodine was an ordinary cat.
The French scientist Bernard Courtois during the years of the Napoleonic Wars noticed that in the products obtained from the ashes of seaweed, which were thrown onto the coast of France, there is some substance that corrodes iron and copper vessels. But neither Courtois himself nor his assistants knew how to isolate this substance from the ashes of algae. Chance helped speed up the discovery.
At his small saltpeter plant in Dijon, Courtois was going to conduct several experiments. There were vessels on the table, one of which contained an alcoholic tincture of seaweed, and the other a mixture of sulfuric acid and iron. On the shoulders of the scientist sat his beloved cat.
There was a knock on the door, and the frightened cat jumped down and ran away, brushing the flasks on the table with its tail. The vessels broke, the contents mixed, and suddenly a violent chemical reaction began. When a small cloud of vapors and gases settled, the surprised scientist saw some kind of crystalline coating on the objects and debris. Courtois began to explore it. Crystals to anyone before this unknown substance were called "iodine".
So a new element was discovered, and Bernard Courtois's domestic cat went down in history.
Experience No. 6 "Obtaining iodine crystals"
Reagents and equipment: tincture of pharmaceutical iodine, water, a glass or a cylinder, a napkin.
Experiment: We mix water with tincture of iodine in the proportion: 10 ml of iodine and 10 ml of water. And put everything in the refrigerator for 3 hours. During cooling, the iodine will precipitate at the bottom of the glass. We drain the liquid, take out the iodine precipitate and put it on a napkin. Squeeze with napkins until the iodine begins to crumble.
Discussion: This chemical experiment is called extraction or extraction of one component from another. In this case, the water extracts the iodine from the spirit lamp solution. Thus, the young researcher will repeat the experience of the cat Courtois without smoke and beating dishes.
Your child will already learn about the benefits of iodine for disinfecting wounds from the movie. Thus, you show that there is an inextricable link between chemistry and medicine. However, it turns out that iodine can be used as an indicator or analyzer of the content of another useful substance - starch. The following experience will introduce the young experimenter to a separate very useful chemistry - analytical.
Experience No. 7 "Iodine-indicator of starch content"
Reagents and equipment: fresh potatoes, pieces of banana, apple, bread, a glass of diluted starch, a glass of diluted iodine, a pipette.
Experiment: We cut the potatoes into two parts and drip diluted iodine on it - the potatoes turn blue. Then we drip a few drops of iodine into a glass of diluted starch. The liquid also turns blue.
We drip with a pipette iodine dissolved in water on an apple, banana, bread, in turn.
Watching:
The apple didn't turn blue at all. Banana - slightly blue. Bread - turned blue very much. This part of the experience shows the presence of starch in various foods.
Discussion: Starch, reacting with iodine, gives a blue color. This property gives us the ability to detect the presence of starch in various foods. Thus, iodine is, as it were, an indicator or analyzer of starch content.
As you know, starch can be converted into sugar, if you take an unripe apple and drop iodine, it will turn blue, since the apple is not yet ripe. As soon as the apple ripens, all the starch contained will turn into sugar and the apple does not turn blue at all when treated with iodine.
The following experience will be useful for children who have already started studying chemistry at school. It introduces concepts such as chemical reaction, compound reaction, and qualitative reaction.
Experiment No. 8 "Flame coloring or compound reaction"
Reagents and equipment: tweezers, table salt, spirit lamp
Experiment: Take with tweezers a few crystals of coarse salt table salt. Let's hold them over the flame of the burner. The flame will turn yellow.
Discussion: This experiment makes it possible to carry out a chemical combustion reaction, which is an example of a compound reaction. Due to the presence of sodium in the composition of table salt, during combustion, it reacts with oxygen. As a result, a new substance is formed - sodium oxide. The appearance of a yellow flame indicates that the reaction has passed. Such reactions are qualitative reactions to compounds containing sodium, that is, it can be used to determine whether sodium is present in a substance or not.
More than 160 experiments that clearly demonstrate the laws of physics and chemistry were filmed, edited and posted online on the scientific and educational video channel "Simple Science". Many of the experiments are so simple that they are easy to repeat at home - they do not require special reagents and devices. About how to make simple chemical and physical experiments at home not only interesting, but also safe, which experiments will captivate kids and which ones will be curious for schoolchildren, Denis Mokhov, author and editor-in-chief of the scientific and educational video channel " Simple Science".
- How did your project start?
– Since childhood, I love different experiences. As long as I can remember, I collected various ideas for experiments, in books, TV shows, so that later I could repeat them myself. When I became a father myself (my son Mark is now 10 years old), it was always important for me to keep my son's curiosity and, of course, to be able to answer his questions. After all, like any child, he looks at the world in a completely different way than adults. And at some point, his favorite word was the word "why?". It is from these "why?" home experiments began. To tell is one thing, but to show is quite another. It can be said that my child's curiosity served as an impetus for the creation of the Simple Science project.
- How old was your son when you started practicing home experiments?
– We have been doing experiments at home since the moment my son went to kindergarten, after about two years. At first it was quite simple experiments with water and balance. For example, jet pack , paper flowers on the water , two forks on a match head. My son immediately liked these funny "tricks". Moreover, he, like me, is always interested not so much in observing as in repeating them on his own.
–
With young children, you can conduct interesting experiments in the bathroom: with boat and liquid soap, paper boat and balloon,
tennis ball and water jet. From birth, a child strives to learn everything new; he will definitely like these spectacular and colorful experiences.
When we are dealing with schoolchildren, even first-graders, here we can already turn around with might and main. At this age, children are interested in relationships, they will carefully observe the experiment, and then look for an explanation of why things happen this way and not otherwise. Here it is just possible to explain the essence of the phenomenon, the causes of interactions, even if not in entirely scientific terms. And when a child encounters similar phenomena at school lessons (including in high school), the teacher’s explanations will be clear to him, because he already knows this from childhood, he has personal experience in this area.
Interesting experiments for younger students
**Pack pierced with pencils**
**Egg in a bottle**
rubber egg
** - Denis, what would you advise parents in terms of the safety of home experiments? ** - I would conditionally divide the experiments into three groups: harmless, experiments that require accuracy and experiments, and the last **-** experiments that require safety precautions. If you demonstrate how two forks stand on the tip of a toothpick, then this is the first case. If you are doing an experiment with atmospheric pressure, when a glass of water is covered with a sheet of paper and then turned over, then you need to be careful not to spill water on electrical appliances **–** do the experiment over the sink. When experimenting with fire, keep a vessel of water ready just in case. And if you use any reagents or chemicals (even ordinary vinegar), then it’s better to go out into the fresh air or to a well-ventilated area (for example, a balcony) and be sure to put on safety glasses for the child (you can use ski, construction or sun glasses).
**- Where can I get reagents and accessories? ** **- ** At home, for experiments with children under 10 years old, it is best to use publicly available reagents and accessories. This is what each of us has in the kitchen: soda, salt, chicken egg, forks, glasses, liquid soap. Safety is paramount in our business. Especially if your “young chemist”, after successful experiments with you, tries to repeat the experiments on his own. Just do not need to ban anything, all children are inquisitive, and the ban will act as an additional incentive! It is better to explain to the child why some experiments cannot be done without adults, that there are certain rules, somewhere an open area is needed for the experiment, somewhere rubber gloves or glasses are needed. **– Have there been cases in your practice when an experiment turned into an emergency situation?** **– ** Well, there was nothing like that at home. But in the editorial office of "Simple Science" incidents often happen. Once, while shooting an experiment with acetone and chromium oxide, we miscalculated the proportions a little, and the experiment almost got out of control.
And recently, while shooting for the Science 2.0 channel, we had to do a spectacular experiment when 2000 table tennis balls fly out of a barrel and fall beautifully to the floor. So, the barrel turned out to be rather fragile and instead of a beautiful flight of balls, an explosion with a deafening roar turned out. **– Where do you get ideas for experiments?** **–** We find ideas on the Internet, in popular science books, in the news about some interesting discoveries or unusual phenomena. The main criteria **–** entertainment and simplicity. We try to choose those experiments that are easy to repeat at home. True, sometimes we release "delicacy" **-** experiments that require unusual devices, special ingredients, but this does not happen too often. Sometimes we consult with professionals from various fields, for example, when doing experiments on superconductivity at low temperatures or in chemical experiments when rare reagents are required. Our viewers (whose number exceeded 3 million this month) also help us in the search for ideas, for which we, of course, thank them.
We bring to your attention 10 amazing magic tricks, experiments, or science shows that you can do with your own hands at home.
At your child's birthday party, weekend or vacation, make the most of your time and become the center of attention of many eyes! 🙂
An experienced organizer of scientific shows helped us in preparing the post - Professor Nicolas. He explained the principles behind a particular focus.
1 - Lava Lamp
1. Surely many of you have seen a lamp that has a liquid inside that imitates hot lava. Looks magical.
2. Water is poured into sunflower oil and food coloring (red or blue) is added.
3. After that, we add effervescent aspirin to the vessel and observe a striking effect.
4. During the reaction, colored water rises and falls through the oil without mixing with it. And if you turn off the light and turn on the flashlight, the "real magic" will begin.
: “Water and oil have different densities, and also have the property of not mixing, no matter how we shake the bottle. When we add effervescent tablets inside the bottle, they dissolve in water and begin to release carbon dioxide and set the liquid in motion.”
Want to put on a real science show? More experiences can be found in the book.
2 - Experience with soda
5. Surely at home or in a nearby store there are several cans of soda for the holiday. Before you drink them, ask the guys the question: “What happens if you submerge soda cans in water?”
Drown? Will they swim? Depends on the soda.
Invite the children to guess in advance what will happen to a particular jar and conduct an experiment.
6. We take the cans and gently lower them into the water.
7. It turns out that despite the same volume, they have different weights. That is why some banks sink and others do not.
Commentary by Professor Nicolas: “All our cans have the same volume, but the mass of each can is different, which means that the density is different. What is density? This is the value of mass divided by volume. Since the volume of all cans is the same, the density will be higher for one of them, whose mass is greater.
Whether a jar will float in a container or sink depends on the ratio of its density to that of water. If the density of the can is less, then it will be on the surface, otherwise the can will go to the bottom.
But what makes a regular cola can denser (heavier) than a diet drink can?
It's all about the sugar! Unlike ordinary cola, where granulated sugar is used as a sweetener, a special sweetener is added to diet cola, which weighs much less. So how much sugar is in a typical soda can? The difference in mass between regular soda and its dietary counterpart will give us the answer!”
3 - Paper cover
Ask the audience a question: “What happens if you turn a glass of water over?” Of course it will spill! And if you press the paper to the glass and turn it over? The paper will fall and the water will still spill on the floor? Let's check.
10. Carefully cut out the paper.
11. Put on top of the glass.
12. And carefully turn the glass over. The paper has stuck to the glass, as if magnetized, and the water does not pour out. Wonders!
Commentary by Professor Nicolas: “Although it’s not so obvious, but in fact we are in the real ocean, only in this ocean there is not water, but air that presses on all objects, including you and me, we just got used to it to this pressure that we do not notice it at all. When we cover a glass of water with a piece of paper and turn it over, water presses on the sheet on one side, and air on the other side (from the very bottom)! The air pressure turned out to be greater than the pressure of the water in the glass, so the leaf does not fall.
4 - Soap Volcano
How to make a small volcano erupt at home?
14. You will need baking soda, vinegar, some dish detergent and cardboard.
16. Dilute vinegar in water, add washing liquid and tint everything with iodine.
17. We wrap everything with dark cardboard - this will be the “body” of the volcano. A pinch of soda falls into the glass, and the volcano begins to erupt.
Commentary by Professor Nicolas: “As a result of the interaction of vinegar with soda, a real chemical reaction occurs with the release of carbon dioxide. And liquid soap and dye, interacting with carbon dioxide, form a colored soap foam - that's the eruption.
5 - Candle pump
Can a candle change the laws of gravity and lift water up?
19. We put a candle on a saucer and light it.
20. Pour tinted water on a saucer.
21. Cover the candle with a glass. After a while, the water will be drawn into the glass against the laws of gravity.
Commentary by Professor Nicolas: What does the pump do? Changes pressure: increases (then water or air begins to “run away”) or, conversely, decreases (then gas or liquid begins to “arrive”). When we covered the burning candle with a glass, the candle went out, the air inside the glass cooled, and therefore the pressure decreased, so the water from the bowl began to be sucked in.
Games and experiments with water and fire are in the book "Experiments of Professor Nicolas".
6 - Water in the sieve
We continue to study the magical properties of water and surrounding objects. Ask someone present to put on a bandage and pour water through it. As we can see, it passes through the holes in the bandage without any difficulty.
Bet with others that you can make it so that water will not pass through the bandage without any additional tricks.
22. Cut off a piece of bandage.
23. Wrap a bandage around a glass or champagne glass.
24. Turn the glass over - the water does not spill out!
Commentary by Professor Nicolas: “Due to such a property of water as surface tension, water molecules want to be together all the time and it is not so easy to separate them (they are such wonderful girlfriends!). And if the size of the holes is small (as in our case), then the film does not tear even under the weight of water!”
7 - Diving bell
And to secure your honorary title of Water Mage and Master of the Elements, promise that you can deliver paper to the bottom of any ocean (or bath or even a basin) without soaking it.
25. Have those present write their names on a piece of paper.
26. We fold the sheet, put it in a glass so that it rests against its walls and does not slide down. Immerse the leaf in an inverted glass to the bottom of the tank.
27. Paper stays dry - water can't get to it! After you pull out the sheet - let the audience make sure that it is really dry.
