Ordinary experiments. description of materials used for the experiment

Incredible facts

Darwin flowers

Most people are familiar with the work of Charles Darwin and his famous journey to South America. He made his most important discoveries in the Galapagos Islands, where each of the 20 islands had its own unique set of species perfectly adapted to its environment. But few people know about Darwin's experiments after he returned to England. Some of them focused on orchids.

In the process of growing and studying several types of orchids, he realized that complex flowers orchids are an adaptation that allows flowers to attract insects, which then transfer pollen to neighboring plants. Each insect is specifically designed to pollinate one type of orchid. Take, for example, an orchid Star of Bethlehem(Angraecum sesquipedale), in which nectar is stored at a depth of 30 centimeters. Darwin foresaw that there must be an insect that pollinates this type of orchid. Of course, in 1903, scientists discovered a species called the twilight butterfly, which has a long proboscis that can reach the nectar of this type of orchid.

Darwin used the data he collected about orchids and their insect pollinators to strengthen his theory of natural selection. He argued that cross-pollinated orchids are more viable than self-pollinated ones because selfing reduces genetic diversity, which ultimately has a direct impact on the survival of the species. Thus, three years after he first described natural selection In On the Origin of Species, Darwin carried out several more experiments on flowers and strengthened his claims about the framework of evolution.

DNA decoding

James Watson and Francis Crick came very close to deciphering DNA, but their discoveries depend largely on the work of Alfred Hershey and Martha Chase, who carried out the famous 1952 this day an experiment that helped them determine how DNA molecules are related to heredity. Hershey and Chase were working with a type of virus known as a bacteriophage. This virus, consisting of a protein coat that surrounds a strand of DNA, infects a bacterial cell, which programs it to produce new infected cells. The virus then kills the cell and new viruses are born. Hershey and Chase knew about this, but they did not know which component—protein or DNA—was responsible. They didn't know this until they conducted their ingenious "blender" experiment, which led them to DNA ribonucleic acids.

After the Hershey and Chase experiment, many scientists such as Rosalind Franklin focused on studying DNA and its molecular structure. Franklin used a technique called X-ray diffraction to study DNA. It involves the "invasion" of X-rays into the fibers of purified DNA. When rays interact with a molecule, they “stray” from their original course and become diffracted. The diffracted beams then form an image of a unique molecule, ready for analysis. Franklin's famous photograph shows the X-shaped curve that Watson and Crick termed the "signature of the DNA molecule." They were also able to determine the width of the spiral by looking at Franklin's image.

First vaccination

Until the global eradication of smallpox in the late 20th century, the disease was a serious problem. In the 18th century, a disease caused by the smallpox virus killed one in ten children born in Sweden and France. “Catching” the virus was the only possibility of “treatment.” This led to people themselves trying to catch the virus from purulent ulcers. Unfortunately, many of them died during the dangerous attempt of self-vaccination.

Edward Jenner, a British doctor, began studying the virus and developing effective treatments. The genesis of his experiments was the observation that milkmaids living in his hometown were often infected with the cowpox virus, a non-fatal disease similar to smallpox. Milkmaids who contracted cowpox seemed to be protected from smallpox infection, so in 1796 Jenner decided to test whether a person could develop immunity to smallpox if infected with the cowpox virus. The boy on whom Jenner decided to conduct his experiment was named James Phipps. Jenner cut Phipps' arm and infected him with cowpox. After some time the boy recovered. 48 days later, the doctor introduced the smallpox virus into his body and found that the boy was immune.

Scientists now know that the vaccinia and smallpox viruses are so similar that the human immune system is unable to distinguish them.

Proof of the existence of the atomic nucleus

Physicist Ernest Rutherford has already won Nobel Prize in 1908 for his radioactive work, during which time he also began conducting experiments to reveal the structure of the atom. The experiments were based on his previous research, which showed that radioactivity consists of two types of rays - alpha and beta. Rutherford and Hans Geiger discovered that alpha rays are streams of positively charged particles. When he released alpha particles onto the screen, they created a clear and sharp image. But if a thin sheet of mica was placed between the alpha radiation source and the screen, the resulting image was blurry. It was clear that the mica scattered some alpha particles, but how and why this happened was not understood at the time.

In 1911, a physicist placed a thin sheet of gold foil between an alpha radiation source and a screen, 1-2 atoms thick. He also placed another screen in front of the alpha radiation source in order to understand which particles were deflected back. On the screen behind the foil, Rutherford observed a diffuse pattern similar to what he saw when using a mica sheet. What he saw on the screen in front of the foil surprised Rutherford, as several alpha particles bounced straight back. Rutherford concluded that the strong positive charge at the heart of the gold atoms sent the alpha particles back to the source. He called this strong positive charge the "nucleus", and stated that, compared to the overall size of the atom, its nucleus must be very small, otherwise many more particles would return back. Today, scientists, like Rutherford, visualize atoms: small, positively charged nuclei surrounded by large, mostly empty space inhabited by a few electrons.

X-ray

We've already talked about Franklin's X-ray diffraction research, but his work owes a lot to Dorothy Crowfoot Hodgkin, one of three women to win the Nobel Prize in Chemistry. In 1945, Hodgkin was considered one of the world's leading practitioners of X-ray diffraction techniques, so it is not surprising that she was the one who eventually showed the structure of one of the most important chemicals in medicine today - penicillin. Alexander Fleming discovered a bacteria-killing substance back in 1928, but it took scientists some more time to purify the substance in order to develop effective treatment. Thus, with the help of penicillin atoms, Hodgkin was able to create semi-synthetic derivatives of penicillin, which turned out to be a revolution in the fight against infections.

Hodgkin's research became known as X-ray crystallography. For the first time, chemists crystallized the compounds they wanted to analyze. It was a challenge. After testing penicillin crystals by two different companies, Hodgkin fired X-ray waves through the crystals and allowed radiation to "penetrate the object being tested." When X-rays interacted with the electrons of the object under study, the rays became slightly diffracted. This resulted in a clear pattern of dots appearing on the film. By analyzing the position and brightness of these dots and performing many calculations, Hodgkin determined exactly how the atoms in the penicillin molecule were arranged.

A few years later, she used the same technology to reveal the structure of vitamin B12. She received the Nobel Prize in Chemistry in 1964, an honor that no other woman has received.

The emergence of life

In 1929, biochemists John Haldane and Alexander Oparin independently proposed that there was no free oxygen in the Earth's early atmosphere. Under those harsh conditions, they theorized, organic compounds could form from simple molecules, receiving a serious charge of energy, be it ultraviolet radiation or bright light. Haldane also added that the oceans were likely the first sources of these organic compounds.

American chemists Harold Urey and Stanley Miller decided to test the hypotheses of Oparin and Haldane in 1953. They were able to recreate Earth's early atmosphere by carefully working on controlled, closed system. The role of the ocean was played by a flask with heated water. After the water vapor rose and collected in another container, Urey and Miller added hydrogen, methane and ammonia to simulate an oxygen-free atmosphere. Sparks were then formed in the flask, representing light in the mixture of gases. Finally, a condenser cooled the gases into a liquid, which they then took for analysis.

A week later, Yuri and Miller received surprising results: organic compounds were present in abundance in the cooled liquid. In particular, Miller discovered several amino acids, including glycine, alanine and glutamic acid. Amino acids are the building blocks of proteins, which themselves are key components of both cellular structures and cellular enzymes responsible for the functioning of important chemical reactions. Urey and Miller came to the conclusion that organic molecules could well survive in an oxygen-free environment, which, in turn, did not keep the simplest organisms from appearing.

Creation of light

When light appeared in the 19th century, it remained a mystery that inspired many fascinating experiments. For example, the “double-slit experiment” by Thomas Young, which showed how light waves behave, but not particles. But back then they didn’t know how fast light travels.

In 1878, physicist A.A. Michelson conducted an experiment to calculate the speed of light and prove that it was a finite, measurable quantity. Here's what he did:

1. Firstly, he placed two mirrors far apart on different sides dams near the university campus, positioning them so that the incident light was reflected from one mirror and returned back. He measured the distance between the mirrors and found that it was 605.4029 meters.

3. Using lenses, he focused a beam of light onto a stationary mirror. When a beam of light touched a stationary mirror, it bounced off and was reflected in a rotating mirror, near which Michelson placed a special screen. Due to the fact that the second mirror rotated, the trajectory of the return of the light beam changed slightly. When Michelson measured these deviations, he came up with a figure of 133 mm.

4. Using the data obtained, he was able to measure the speed of light to be 186,380 miles per second (299,949,530 kilometers). The acceptable value for the speed of light today is 299,792,458 km per second. Michelson's measurements showed surprisingly accurate results. Moreover, scientists now have at their disposal more accurate ideas about light and the foundations on which the theories of quantum mechanics and the theory of relativity are built.

Discovery of radiation

1897 was a very important year for Marie Curie. Her first child was born, and just a few weeks after his birth, she went looking for a topic for her doctoral dissertation. Eventually, she decided to study the "uranium rays" first described by Henri Becquerel. Becquerel discovered these rays by accident when he left uranium salts wrapped in an opaque material along with photographic plates in dark room, and when he returned, he discovered that the photographic plates were completely overexposed. Marie Curie chose to study these mysterious rays in order to identify other elements that acted in a similar way.

Already at an early stage of study, Curie realized that thorium produces the same rays as uranium. She started labeling these unique elements, as "radioactive" and quickly realized that the strength of radiation produced by uranium and thorium depended on the amount of thorium and uranium. In the end, she will be able to prove that the rays are properties of the atoms of a radioactive element. This in itself was a revolutionary discovery, but Curie was stopped by it.

She discovered that pitchblende (uraninite) was more radioactive than uranium, which led her to the idea that there must be an element unknown to her in natural minerals. Her husband Pierre joined the research, and they systematically reduced the amounts of pitchblende until they discovered a new isolated element. They named it polonium, after Mary's homeland of Poland. Soon after, they discovered another radioactive element, which they called radium, from the Latin for "ray." Curie won two Nobel Prizes for her work.

Dog days

Did you know that Ivan Pavlov, the Russian physiologist and chemist and author of the salivation and conditioning experiment in dogs, was not at all interested in psychology or behavior? He was interested in the topics of digestion and blood circulation. In fact, he was studying the digestive system of dogs when he discovered what we know today as “conditioned reflexes.”

In particular, he tried to understand the relationship between salivation and stomach function. Shortly before this, Pavlov had already noted that the stomach does not begin to digest food without salivation, which occurs first. In other words, reflexes in the autonomic nervous system closely connect these two processes with each other. Next, Pavlov decided to find out whether they could external stimuli affect digestion in a similar way. To test this, he started turning the lights on and off while the dog was eating, ticking a metronome, and making a buzzer sound audible. In the absence of these stimuli, the dogs salivated only when they saw and ate food. But after a while, they began to salivate when stimulated by sound and light, even if they were not given food at the time. Pavlov also discovered that this type of conditioning dies if the stimulus is used "incorrectly" too often. For example, if a dog hears a sound signal often, but does not receive food, then after some time, it stops responding to the sound by salivating.

Pavlov published his results in 1903. A year later he received the Nobel Prize in Medicine, not for his work on conditioned reflexes, but "in recognition of his work on the physiology of digestion, by which knowledge of vital aspects has been transformed and expanded."

Stanley Milgram's experiments, which he conducted in the 1960s, still qualify as one of the most famous and controversial scientific experiments. Milgram wanted to find out how far the average person would go to inflict pain on another person under pressure from authority. Here's what he did:

1. Milgram recruited volunteers, ordinary people, who were ordered to inflict some pain on other volunteer actors. The experimenter played the role of an authority figure who was constantly present in the room during the study.

2. Before the start of each test, the authority demonstrated to unsuspecting volunteers how to use a shock device that could shock a person with a discharge of 15-450 volts (increased level of danger).

3. The scientist further noted that they should test how shock can improve word memory through associations. During the experiment, he instructed volunteers to “reward” volunteer actors with shock blows for incorrect answers. The more incorrect answers there were, the higher the voltage level on the device. Moreover, it is worth noting that the device was made on top level: above each switch the voltage corresponding to it was written, from “weak shock” to “hard shock”, the device was equipped with many panels with pointer voltmeters. That is, the subjects did not have the opportunity to doubt the authenticity of the experiment, and the study was structured in such a way that for every correct answer there were three incorrect ones and the authority told the volunteer what “blow” to punish the “incapable student.”

4. The "students" screamed when they received shock blows. After the impact exceeded 150 volts, they demanded release. At the same time, the authority urged volunteers to continue the experiment, not paying attention to the demands of the “students”.

5. Some participants in the experiment wanted to leave after reaching the punishment of 150 volts, but most continued until they reached the maximum shock level of 450 volts.

At the end of the experiments, many spoke out about the unethical nature of this study, but the results obtained were impressive. Milgram proved that ordinary people can hurt an innocent person simply because they received such a command from a powerful authority.

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There are very simple experiments that children remember for the rest of their lives. The guys may not fully understand why this is all happening, but when time will pass and they find themselves in a physics or chemistry lesson, a very clear example will certainly emerge in their memory.

website collected 7 interesting experiments that children will remember. Everything you need for these experiments is at your fingertips.

Fireproof ball

Will need: 2 balls, candle, matches, water.

Experience: Inflate a balloon and hold it over a lit candle to demonstrate to children that the fire will make the balloon burst. Then pour plain tap water into the second ball, tie it and bring it to the candle again. It turns out that with water the ball can easily withstand the flame of a candle.

Explanation: The water in the ball absorbs the heat generated by the candle. Therefore, the ball itself will not burn and, therefore, will not burst.

Pencils

You will need: plastic bag, simple pencils, water.

Experience: Fill the plastic bag halfway with water. Use a pencil to pierce the bag right through where it is filled with water.

Explanation: If you pierce a plastic bag and then pour water into it, it will pour out through the holes. But if you first fill the bag halfway with water and then pierce it with a sharp object so that the object remains stuck into the bag, then almost no water will flow out through these holes. This is due to the fact that when polyethylene breaks, its molecules are attracted closer to each other. In our case, the polyethylene is tightened around the pencils.

Unbreakable balloon

You will need: a balloon, a wooden skewer and some dishwashing liquid.

Experience: Coat the top and bottom with the product and pierce the ball, starting from the bottom.

Explanation: The secret of this trick is simple. In order to preserve the ball, you need to pierce it at the points of least tension, and they are located at the bottom and at the top of the ball.

Cauliflower

Will need: 4 cups of water, food coloring, cabbage leaves or white flowers.

Experience: Add any color of food coloring to each glass and place one leaf or flower in the water. Leave them overnight. In the morning you will see that they are colored different colors.

Explanation: Plants absorb water and thereby nourish their flowers and leaves. This happens due to the capillary effect, in which water itself tends to fill the thin tubes inside the plants. This is how flowers, grass, and large trees feed. By sucking in tinted water, they change color.

floating egg

Will need: 2 eggs, 2 glasses of water, salt.

Experience: Carefully place the egg in a glass with a simple clean water. As expected, it will sink to the bottom (if not, the egg may be rotten and should not be returned to the refrigerator). Pour warm water into the second glass and stir 4-5 tablespoons of salt in it. For the purity of the experiment, you can wait until the water cools down. Then place the second egg in the water. It will float near the surface.

Explanation: It's all about density. The average density of an egg is much greater than that of plain water, so the egg sinks down. And the density of the salt solution is higher, and therefore the egg rises up.

Crystal lollipops

Will need: 2 cups of water, 5 cups of sugar, wooden sticks for mini kebabs, thick paper, transparent glasses, saucepan, food coloring.

Experience: In a quarter glass of water, boil sugar syrup with a couple of tablespoons of sugar. Sprinkle some sugar onto the paper. Then you need to dip the stick in the syrup and collect the sugar with it. Next, distribute them evenly on the stick.

Leave the sticks to dry overnight. In the morning, dissolve 5 cups of sugar in 2 glasses of water over a fire. You can leave the syrup to cool for 15 minutes, but it should not cool too much, otherwise the crystals will not grow. Then pour it into jars and add different food colorings. Place the prepared sticks in a jar of syrup so that they do not touch the walls and bottom of the jar; a clothespin will help with this.

Explanation: As the water cools, the solubility of sugar decreases, and it begins to precipitate and settle on the walls of the vessel and on your stick seeded with sugar grains.

Lighted match

Will be needed: Matches, flashlight.

Experience: Light a match and hold it at a distance of 10-15 centimeters from the wall. Shine a flashlight on the match and you will see that only your hand and the match itself are reflected on the wall. It would seem obvious, but I never thought about it.

Explanation: Fire does not cast shadows because it does not prevent light from passing through it.

Experiment

Experiment(from lat. experimentum- test, experiment) in the scientific method - a method of studying a certain phenomenon under controlled conditions. Differs from observation by active interaction with the object being studied. Typically, an experiment is carried out as part of a scientific research and serves to test a hypothesis and establish causal relationships between phenomena. Experiment is the cornerstone of the empirical approach to knowledge. Popper's criterion puts forward the possibility of setting up an experiment as the main difference scientific theory from pseudoscientific. An experiment is a research method that is reproduced under the described conditions an unlimited number of times and gives an identical result.

Experiment models

There are several experimental models: A flawless experiment is an experimental model that cannot be implemented in practice, used by experimental psychologists as a standard. This term was introduced into experimental psychology by Robert Gottsdanker, the author of the famous book “Fundamentals of Psychological Experiments,” who believed that the use of such a sample for comparison would lead to more effective improvement of experimental techniques and identification possible errors in planning and conducting a psychological experiment.

A random experiment (random test, random experiment) is a mathematical model of a corresponding real experiment, the result of which cannot be accurately predicted. The mathematical model must satisfy the following requirements: it must be adequate and adequately describe the experiment; the set of observed results must be determined within the framework of the mathematical model under consideration with strictly defined fixed initial data described within the framework of the mathematical model; there must be a fundamental possibility of carrying out an experiment with a random outcome as many times as desired with constant input data; the requirement must be proven or the hypothesis about the stochastic stability of the relative frequency for any observed result defined within the mathematical model must be accepted a priori.

An experiment is not always implemented as intended, so a mathematical equation was invented for the relative frequency of experiment implementations:

Let there be some real experiment and let A denote the result observed within this experiment. Let n experiments be carried out in which result A may or may not be realized. And let k be the number of realizations of the observed result A in n tests performed, assuming that the tests performed are independent.

Types of experiments

Physical experiment

Physical experiment - a way of knowing nature, which consists in studying natural phenomena in specially created conditions. Unlike theoretical physics, which explores mathematical models of nature, physical experiment is designed to explore nature itself.

It is disagreement with the result of a physical experiment that is the criterion of error physical theory, or more precisely, the inapplicability of the theory to the world around us. The converse statement is not true: agreement with experiment cannot be proof of the correctness (applicability) of the theory. That is, the main criterion for the viability of a physical theory is verification by experiment.

Ideally, experimental physics should only provide description results of the experiment, without any interpretations. However, in practice this is not achievable. Interpretation of the results of a more or less complex physical experiment inevitably relies on the fact that we have an understanding of how all the elements of the experimental setup behave. Such an understanding, in turn, cannot but rely on some theories.

Computer experiment

A computer (numerical) experiment is an experiment on a mathematical model of a research object on a computer, which consists of calculating other parameters of the model based on some parameters and, on this basis, drawing conclusions about the properties of the object described by the mathematical model. This type experiment can only be conditionally attributed to experiment, because it does not reflect natural phenomena, but is only a numerical implementation of a human-created mathematical model. Indeed, with incorrectness in the mat. model - its numerical solution can be strictly divergent from physical experiment.

Psychological experiment

Psychological experiment - an experiment conducted under special conditions to obtain new scientific knowledge through the purposeful intervention of the researcher in the life activity of the subject.

Thought experiment

Thought experiment in philosophy, physics and some other fields of knowledge - view cognitive activity, in which the structure of a real experiment is reproduced in the imagination. As a rule, a thought experiment is carried out within the framework of a certain model (theory) to check its consistency. When conducting a thought experiment, contradictions in the internal postulates of the model or their incompatibility with external (in relation to this model) principles that are considered unconditionally true (for example, with the law of conservation of energy, the principle of causality, etc.) may be revealed.

Critical experiment

A critical experiment is an experiment whose outcome uniquely determines whether a particular theory or hypothesis is true. This experiment must produce a predicted result that cannot be inferred from other, generally accepted hypotheses and theories.

Literature

• Vizgin V.P. Hermeticism, experiment, miracle: three aspects of the genesis of science in modern times // Philosophical and religious sources of science. M., 1997. P.88-141.

Links

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Synonyms:

See what “Experiment” is in other dictionaries:

- (from Latin experimentum trial, experience), a method of cognition, with the help of which phenomena of reality are studied under controlled and controlled conditions. E. is carried out on the basis of a theory that determines the formulation of tasks and its interpretation... ... Philosophical Encyclopedia

experiment- An invitation to a person to voluntarily live, experience, feel what is relevant for him or to go on a conscious experiment, recreating during therapy a situation that is controversial or dubious for him (primarily in symbolic form). Brief explanatory... ... Great psychological encyclopedia

Nobody believes in a hypothesis except the one who put it forward, but everyone believes in the experiment except the one who conducted it. No amount of experimentation can prove a theory; but one experiment is enough to refute it... Consolidated encyclopedia of aphorisms

Experiment- (Latin experimentum – sonau, baikau, tazhiribe) – nәrseler (objectiler) men kubylystardy baqylanylatyn zhane baskarylatyn zhagdaylarda zertteytin empiriyalyk tanym adіsi. Experiment adis retinde Zhana zamanda paida bolda (G. Galileo). Nowadays a philosopher... Philosophy terminerdin sozdigi

- (lat.). First experience; everything that a natural scientist uses to force the forces of nature to act under certain conditions, as if artificially causing the phenomena occurring in it. Dictionary foreign words, included in the Russian... ... Dictionary of foreign words of the Russian language

See experience... Dictionary of Russian synonyms and similar expressions. under. ed. N. Abramova, M.: Russian Dictionaries, 1999. experiment, test, experience, trial; research, verification, attempt Dictionary of Russian synonyms ... Synonym dictionary

EXPERIMENT, experiment, husband. (lat. experimentum) (book). Scientifically conducted experiment. Chemical experiment. Physical experiment. Carry out an experiment. || In general, an experience, an attempt. Educational work does not allow risky experiments... ... Ushakov's Explanatory Dictionary

Experiment- Experiment ♦ Expérimentation Active, deliberate experience; the desire not so much to hear real reality (experience) and not even so much to listen to it (observation), but to try to ask questions of it. There is a special concept... ... Sponville's Philosophical Dictionary

Parents of little fidgets can surprise them with experiments that can be carried out at home. Light, but at the same time surprising and delightful, they can not only diversify a child’s leisure time, but also allow them to look at familiar things with completely different eyes. And discover their properties, functions, purpose.

Young naturalists

Experiments at home, great for children under 10 years old - The best way Help your child gain practical experience that will be useful to him in the future.

Safety precautions when conducting experiments

To ensure that educational experiments are not overshadowed by troubles and injuries, it is enough to remember a few simple but important rules.

Safety comes first

1. Before you start working with chemicals, the work surface must be protected by covering it with film or paper. This will save parents from unnecessary cleaning and allow them to save appearance and functionality of furniture.
2. During work, you do not need to get too close to the reagents, bending over them. Especially if your plans include chemical experiments for young children that involve unsafe substances. The measure will protect the mucous membranes of the mouth and eyes from irritation and burns.
3. If possible, you should use protective equipment: gloves, glasses. They must be suitable in size for the child and not interfere with him during the experiment.

Simple experiments for little ones

Developmental experiences and experiments for very young children (or for children under 10 years old) are usually simple and do not require parents to have any special skills or rare or expensive equipment. But the joy of discovery and miracle, which is so easy to do with your own hands, will remain with him for a long time.

For example, children will be indescribably delighted by a real seven-color rainbow, which they can create themselves with the help of an ordinary mirror, a container of water and a sheet of white paper.

Rainbow in a Bottle Experience

To begin with, place a mirror at the bottom of a small basin or bathtub. Then, it is filled with water; and the light of the lantern is directed onto the mirror. After the light is reflected and passes through the water, it is decomposed into its component colors, becoming the same rainbow that can be seen on a sheet of white paper.

Another very simple and beautiful experiment can be carried out using ordinary water, wire and salt.

To begin the experiment, you need to prepare a supersaturated salt solution. Calculating the required concentration of a substance is quite simple: when required quantity salt in water, it stops dissolving when the next portion is added. It is very good to use warm distilled water for this purpose. To make the experiment more successful, the finished solution can also be poured into another container - this will remove dirt and make it cleaner.

Experience "Salt on a Wire"

When everything is ready, a small piece of copper wire with a loop at the end is lowered into the solution. The container itself is removed to a warm place and left there for a certain time. As the solution begins to cool, the solubility of the salt will decrease and it will begin to settle on the wire in the form of beautiful crystals. You will be able to notice the first results within a few days. By the way, you can use not only ordinary, straight wire in the experiment: by twisting fancy figures from it, you can grow crystals of very different sizes and shapes. By the way, this experiment will give the child great idea New Year's toys in the form of real ice snowflakes - you just need to find a flexible wire and form a beautiful symmetrical snowflake out of it.

Invisible ink can also make a lasting impression on a child. It’s very simple to prepare them: just take a cup of water, matches, cotton wool, half a lemon. And a sheet on which you can write text.

Invisible ink can be purchased ready-made

First you need to mix in a cup equal amount lemon juice and water. Then, a little cotton wool is wrapped around a toothpick or a thin match. The resulting “pencil” is dipped into the mixture in the resulting liquid; Then they can write any text on a piece of paper.

Even though the words on paper will be completely invisible at first, it will be very easy to manifest them. To do this, a sheet of already dried ink needs to be brought to the lamp. The written words will immediately appear on a heated sheet of paper.

Which child doesn't love balloons?

It turns out that you can even inflate an ordinary balloon in a very original way. To do this, dissolve one spoon of baking soda in a bottle of water. And in another cup, mix the juice of one lemon and three tablespoons of vinegar. Afterwards, the contents of the cup are introduced into the bottle (for convenience, you can use a small funnel). The ball must be placed on the neck of the bottle as quickly as possible until the chemical reaction is completed. During this time carbon dioxide will be able to quickly inflate the balloon under pressure. To prevent the ball from jumping off the neck of the bottle, it can be secured with electrical tape or tape.

"Inflate the balloon" experiment

Colored milk looks very interesting and unusual, the colors of which will move, intricately mixing with each other. For this experiment, you need to pour some whole milk into a plate and add a few drops of food coloring to it. Selected areas the liquids will turn different colors, but the spots will remain motionless. How to set them in motion? Very simple. It is enough to take a small cotton swab and, after dipping it in detergent, bring it to the surface of the colored milk. Having reacted with milk fat molecules, the molecules detergent make him move.

Experience “Drawings on milk”

Important! Skim milk is not suitable for this experiment. Only whole ones can be used!

Surely all children have had the opportunity to observe funny air bubbles in mineral or sweet water at home and on the street. But are they strong enough to lift a grain of corn or raisin to the surface? It turns out yes! To check this, just pour any sparkling water into a bottle, and then throw some corn or raisins into it. The child will see for himself how easily, under the influence of air bubbles, both corn and raisins will begin to rise up, and then, having reached the surface of the liquid, fall down again.

Experiments for older children

Older children (from 10 years old) can be offered more complex chemical experiments that require more components. These experiments are a little more difficult for older children, but children can already take part in them.

To comply with safety precautions, children under 10 years of age should conduct experiments under the strict supervision of adults, mainly as a spectator. Children over 10 years old can take a more active part in the experiments.

An example of such an experiment would be the creation lava lamp. Surely many children dream of such a miracle. But it’s much more pleasant to make it yourself, using simple components that are probably found in every home.

Lava Lamp Experience

The basis of the lava lamp will be a small jar or an ordinary glass. In addition, for the experiment you will need vegetable oil, water, salt and a little food coloring.

The jar or other container used as the base of the lamp is filled two-thirds with water and one-third with oil. Since oil is much lighter in weight than water, it will remain on its surface without mixing with it. Then, a little food coloring is added to the jar - this will give the lava lamp color and make the experiment more beautiful and spectacular. And after that, add a teaspoon of salt to the resulting mixture. For what? Salt causes the oil to sink to the bottom in the form of bubbles, and then, dissolving, pushes them up.

Next chemical experiment will help make a school subject like geography exciting and interesting.

Making a volcano with your own hands

After all, studying volcanoes is much more interesting when there is not just a dry book text nearby, but a whole model! Especially if you can easily do it at home with your own hands, using available means at hand: sand, food coloring, soda, vinegar and a bottle are perfect.

To begin with, a bottle is placed on a tray - it will become the basis of the future volcano. Around it you need to mold a small cone of sand, clay or plasticine - this way the mountain will take on a more complete and believable appearance. Now you need to cause a volcanic eruption: a little warm water is poured into the bottle, then a little soda and food coloring (red or orange color). The finishing touch will be a quarter glass of vinegar. Having reacted with soda, the vinegar will begin to actively push the contents of the bottle out. This explains interesting effect eruptions, which can be observed with a child.

A volcano can be made from toothpaste

Can paper burn without being burned?

It turns out yes. And an experiment with fireproof money will easily prove this. To do this, a ten-ruble banknote is immersed in a 50% alcohol solution (water is mixed with alcohol in a 1 to 1 ratio, a pinch of salt is added to it). After the bill has been thoroughly soaked, excess liquid is removed from it, and the bill itself is set on fire. Once it flares up, it will begin to burn, but will not burn out at all. This experience is quite simple to explain. The temperature at which alcohol burns is not high enough to evaporate the water. Thanks to this, even after the substance burns out completely, the money will remain slightly damp, but absolutely intact.

Experiments with ice are always a success

Young nature lovers can be encouraged to germinate seeds at home without using soil. How it's done?

A little cotton wool is placed in the eggshell; it is actively moistened with water, and then some seeds (for example, alfalfa) are placed in it. In just a few days you will be able to notice the first shoots. Thus, soil is not always needed for seed germination - only water is enough.

And the next experiment, which is easy to do at home for children, will certainly appeal to girls. After all, who doesn’t like flowers?

A painted flower can be given to your mother

Especially the most unusual, bright colors! Thanks to simple experience right in front of the amazed children, simple and familiar flowers can turn into the most unexpected color. Moreover, this is extremely simple to do: just put the cut flower in water with food coloring added to it. Climbing up the stem to the petals, chemical dyes will color them in the colors you want. To better absorb water, it is better to make a cut diagonally - this way it will have the maximum area. In order for the color to appear brighter, it is advisable to use light or white flowers. An even more interesting and fantastic effect will be obtained if, before starting the experiment, the stem is split into several parts and each of them is immersed in its own glass of colored water.

The petals will turn into all colors at once in the most unexpected and bizarre way. That we will undoubtedly make a lasting impression on the child!

Experience "Colored foam"

Everyone knows that under the influence of gravity, water can only flow downwards. But is it possible to make it rise up the napkin? To conduct this experiment, an ordinary glass is filled about a third with water. The napkin is folded several times to form a narrow rectangle. After this, the napkin unfolds again; Having stepped back a little from the bottom edge, you need to draw a line of colored dots on it, enough large diameter. The napkin is immersed in water so that about one and a half centimeters of its colored part is in it. Having come into contact with the napkin, the water will begin to gradually rise upward, coloring it with multi-colored stripes. This unusual effect occurs due to the fact that, having a porous structure, the fibers of the napkin easily allow water to pass upward.

Experiment with water and napkin

To carry out the following experiment, you will need a small blotter, cookie cutters of different shapes, some gelatin, a transparent bag, a glass and water.

Gelatin water does not mix

Gelatin dissolves in a quarter glass of water; it should swell and increase in volume. Then, the substance is dissolved in a water bath and brought to approximately 50 degrees. the resulting liquid is needed thin layer distribute into a plastic bag. Using gelatin cookie cutters, cut out figures various shapes. After this, you need to lay them on a blotter or napkin, and then breathe on them. Warm breath will cause the gelatin to increase in volume, causing the figures to begin to bend on one side.

Experiments conducted at home with children are very easy to diversify.

Gelatin figures from molds

In winter, you can try to slightly modify the experiment by taking the gelatin figures out onto the balcony or leaving them in the freezer for a while. When the gelatin hardens under the influence of cold, patterns of ice crystals will clearly appear on it.

Conclusion

Description of other experiments

Delight and a sea of ​​positive emotions are what experimenting with adults will bring to curious children. And parents will allow themselves to share the joy of their first discoveries with young researchers. After all, no matter how old a person is, the opportunity to return to childhood at least for a short time is truly priceless.

If you're wondering how to celebrate your child's birthday, you might like the idea of ​​hosting a science show for kids. IN Lately Scientific holidays are becoming increasingly popular. Almost all children enjoy entertaining experiences and experiments. For them it is something magical and incomprehensible, and therefore interesting. The cost of hosting a science show is quite high. But this is not a reason to deny yourself the pleasure of watching the amazed children’s faces. After all, you can get by on our own, I do not resort to the help of animators and holiday agencies.

In this article I have made a selection of simple chemical and physical experiments and experiments that can be carried out without problems at home. Everything you need to carry them out can probably be found in your kitchen or medicine cabinet. You won't need any special skills either. All you need is desire and a good mood.

I tried to collect simple but spectacular experiments that will be interesting to children different ages. For each experiment, I prepared a scientific explanation (it’s not for nothing that I studied to be a chemist!). Whether you explain to your children the essence of what is happening or not is up to you. It all depends on their age and level of training. If the children are small, you can skip the explanation and go straight to spectacular experience, saying only that they will be able to learn the secrets of such “miracles” when they grow up, go to school and begin to study chemistry and physics. Perhaps this will make them interested in studying in the future.

Although I chose the most safe experiments, they still need to be taken very seriously. It is better to perform all manipulations with gloves and a gown, at a safe distance from children. After all, vinegar and potassium permanganate can cause trouble.

And, of course, when holding a children's science show, you need to take care of the image of a mad scientist. Your artistry and charisma will largely determine the success of the event. Transforming from an ordinary person into a funny scientific genius is not at all difficult - all you have to do is tousle your hair, put on big glasses and a white coat, get smeared with soot and make a facial expression appropriate to your new status. This is what a typical mad scientist looks like.

Before putting on a science show on children's party(by the way, this can be not only a birthday, but also any other holiday), all experiments should be done in the absence of children. Rehearse so that there are no unpleasant surprises later. You never know what can go wrong.

Children's experiments can be carried out without a festive occasion - just so that you can spend time with your child in an interesting and useful way.

Choose the experiences you like best and create a holiday script. In order not to overburden children with science, even if it is entertaining, dilute the event with fun games.

Part 1. Chemical show

Attention! When conducting chemical experiments you should be extremely careful.

Foam fountain

Almost all children love foam - the more, the better. Even kids know how to make it: to do this, you need to pour shampoo into the water and shake it well. Can foam form on its own without shaking and also be colored?

Ask the children what they think foam is. What does it consist of and how can it be obtained. Let them express their guesses.

Then explain that foam is bubbles filled with gas. This means that for its formation you need some substance from which the walls of the bubbles will consist, and a gas that will fill them. For example, soap and air. When soap is added to water and stirred, air enters these bubbles from environment. But gas can be obtained in another way - in the process chemical reaction.

Option 1

• hydroperite tablets;
• potassium permanganate;
• liquid soap;
• water;
• glass vessel with a narrow neck (preferably beautiful);
• cup;
• hammer;
• tray.

Setting up the experiment

1. Using a hammer, crush the hydroperite tablets into powder and pour it into the flask.
2. Place the flask on a tray.
3. Add liquid soap and water.
4. Prepare an aqueous solution of potassium permanganate in a glass and pour it into the flask with hydroperide.

After the solutions of potassium permanganate (potassium permanganate) and hydroperide (hydrogen peroxide) merge, a reaction will begin to occur between them, accompanied by the release of oxygen.

4KMnO 4 + 4H 2 O 2 = 4MnO 2 ¯ + 5O 2 + 2H 2 O + 4KOH

Under the influence of oxygen, the soap present in the flask will begin to foam and lick out of the flask, forming a kind of fountain. Due to potassium permanganate, part of the foam will turn pink.

You can see how this happens in the video.

Important: The glass vessel must have a narrow neck. Do not take the resulting foam into your hands and do not give it to children.

Option 2

Another gas, for example carbon dioxide, is also suitable for foam formation. You can paint the foam any color you want.

To carry out the experiment you will need:

• plastic bottle;
• soda;
• vinegar;
• food coloring;
• liquid soap.

Setting up the experiment

1. Pour vinegar into the bottle.
2. Add liquid soap and food coloring.
3. Add baking soda.

Result and scientific explanation

When soda and vinegar interact, a violent chemical reaction occurs, accompanied by the release of carbon dioxide CO 2 .

Under its influence, the soap will begin to foam and lick out of the bottle. The dye will color the foam in the color you choose.

Fun ball

What's a birthday without balloons? Show the children the balloon and ask how to inflate it. The guys, of course, will answer with their mouths. Explain that the balloon is inflated by the carbon dioxide that we exhale. But there is another way to inflate the balloon.

To carry out the experiment you will need:

• soda;
• vinegar;
• bottle;
• balloon.

Setting up the experiment

1. Place a teaspoon of baking soda inside the balloon.
2. Pour vinegar into the bottle.
3. Place the balloon on the neck of the bottle and pour the baking soda into the bottle.

Result and scientific explanation

As soon as soda and vinegar come into contact, a violent chemical reaction will begin, accompanied by the release of carbon dioxide CO 2. Balloon will begin to inflate before our eyes.

CH 3 -COOH + Na + − → CH 3 -COO − Na + + H 2 O + CO 2

If you take a smiley ball, it will make an even greater impression on the guys. At the end of the experiment, tie a balloon and give it to the birthday person.

Watch the video for a demonstration of the experience.

Chameleon

Can liquids change color? If yes, why and how? Before you try the experiment, be sure to ask your children these questions. Let them think. They will remember how water is colored when you rinse a brush with paint in it. Is it possible to discolor the solution?

To carry out the experiment you will need:

• starch;
• alcohol burner;
• test tube;
• cup;
• water.

Setting up the experiment

1. Pour a pinch of starch into a test tube and add water.
2. Drop some iodine. The solution will turn blue.
3. Light the burner.
4. Heat the test tube until the solution becomes colorless.
5. Pour into a glass cold water and immerse the test tube in it so that the solution cools and turns blue again.

Result and scientific explanation

When reacting with iodine, the starch solution turns blue because it forms a compound dark blue I 2 *(C 6 H 10 O 5) n. However, this substance is unstable and, when heated, breaks down again into iodine and starch. When cooled, the reaction goes in the other direction and we again see the solution turning blue. This reaction demonstrates the reversibility of chemical processes and their dependence on temperature.

I 2 + (C 6 H 10 O 5) n => I 2 *(C 6 H 10 O 5) n

(iodine - yellow) (starch - clear) (dark blue)

Rubber egg

All children know that eggshell very fragile and can break at the slightest blow. It would be nice if the eggs didn’t break! Then you wouldn’t have to worry about getting the eggs home when your mom sends you to the store.

To carry out the experiment you will need:

• vinegar;
• raw egg;
• cup.

Setting up the experiment

1. To surprise the children, you need to prepare for this experience in advance. 3 days before the holiday, pour vinegar into a glass and place a raw chicken egg in it. Leave for three days so that the shell has time to completely dissolve.
2. Show the children a glass with an egg and invite everyone to say a magic spell together: “Tryn-dyrin, boom-burym!” Egg, become rubber!”
3. Remove the egg with a spoon, wipe it with a napkin and demonstrate how it can now become deformed.

Result and scientific explanation

Eggshells are made of calcium carbonate, which dissolves when reacted with vinegar.

CaCO 3 + 2 CH 3 COOH = Ca(CH 3 COO) 2 + H 2 O + CO 2

Due to the presence of a film between the shell and the contents of the egg, it retains its shape. Watch the video to see what an egg looks like after vinegar.

Secret letter

Children love everything mysterious, and therefore this experiment will certainly seem like real magic to them.

Take an ordinary ballpoint pen and write a secret message from aliens on a piece of paper or draw some kind of secret sign that no one except the guys present can know about.

When the children read what is written there, tell them that this is a big secret and the inscription must be destroyed. Moreover, it will help you erase the inscription magic water. If you treat the inscription with a solution of potassium permanganate and vinegar, then with hydrogen peroxide, the ink will wash off.

To carry out the experiment you will need:

• potassium permanganate;
• vinegar;
• hydrogen peroxide;
• flask;
• cotton buds;
• ball pen;
• paper;
• water;
• paper towels or napkins;
• iron.

Setting up the experiment

1. Draw a picture or message on a piece of paper with a ballpoint pen.
2. Pour some potassium permanganate into the test tube and add vinegar.
3. Soak a cotton swab in this solution and swipe over the inscription.
4. Take another cotton swab, moisten it with water and wash off the resulting stains.
5. Blot with a napkin.
6. Apply hydrogen peroxide to the inscription and blot it again with a napkin.
7. Iron or place under a press.

Result and scientific explanation

After all the manipulations, you will receive a blank sheet of paper, which will greatly surprise the children.

Potassium permanganate is a very strong oxidizing agent, especially if the reaction occurs in an acidic environment:

MnO 4 ˉ+ 8 H + + 5 eˉ = Mn 2+ + 4 H 2 O

A strong acidified solution of potassium permanganate literally burns many organic compounds, turning them into carbon dioxide and water. To create an acidic environment, our experiment uses acetic acid.

The product of the reduction of potassium permanganate is manganese dioxide Mn0 2, which has a brown color and precipitates. To remove it, we use hydrogen peroxide H 2 O 2, which reduces the insoluble compound Mn0 2 to a highly soluble manganese (II) salt.

MnO 2 + H 2 O 2 + 2 H + = O 2 + Mn 2+ + 2 H 2 O.

I suggest you watch how the ink disappears in the video.

The power of thought

Before setting up the experiment, ask the children how to extinguish a candle flame. They, of course, will answer you that you need to blow out the candle. Ask if they believe you can put out a fire with an empty glass by casting a magic spell?

To carry out the experiment you will need:

• vinegar;
• soda;
• glasses;
• candles;
• matches.

Setting up the experiment

1. Pour baking soda into a glass and fill it with vinegar.
2. Light some candles.
3. Bring a glass of baking soda and vinegar to another glass, tilting it slightly so that the carbon dioxide produced during the chemical reaction flows into the empty glass.
4. Pass a glass of gas over the candles, as if pouring it on the flame. At the same time, make a mysterious expression on your face and say some incomprehensible spell, for example: “Chickens-borers, moors-pli!” Flame, don’t burn anymore!” Children must think that this is magic. You will reveal the secret after the delight.

Result and scientific explanation

When soda and vinegar interact, carbon dioxide is released, which, unlike oxygen, does not support combustion:

CH 3 -COOH + Na + − → CH 3 -COO − Na + + H 2 O + CO 2

CO 2 is heavier than air, and therefore does not fly up, but settles down. Thanks to this property, we have the opportunity to collect it in an empty glass, and then “pour” it onto the candles, thereby extinguishing their flame.

How this happens, watch the video.

Part 2. Entertaining physical experiments

Genie strongman

This experiment will allow children to look at their usual action from a different perspective. Place an empty wine bottle in front of the children (it is better to remove the label first) and push the cork into it. And then turn the bottle upside down and try to shake the cork out. Of course, you won't succeed. Ask the children: is there any way to get the cork out without breaking the bottle? Let them say what they think about this.

Since nothing can be used to pick up the cork through the neck, there is only one thing left to do - try to push it out from the inside. How to do it? You can call the genie for help!

The gin used in this experiment will be a large plastic bag. To enhance the effect, you can decorate the bag with colored markers - draw eyes, nose, mouth, hands, some patterns.

So, to conduct the experiment you will need:

• empty wine bottle;
• cork;
• plastic bag.

Setting up the experiment

1. Twist the bag into a tube and insert it into the bottle so that the handles are on the outside.
2. When turning the bottle over, ensure that the cork is on the side of the bag, closer to the neck.
3. Inflate the bag.
4. Carefully begin to pull the package out of the bottle. The cork will come out along with it.

Result and scientific explanation

As the bag is inflated, it expands inside the bottle, expelling air from it. When we begin to pull out the bag, a vacuum is created inside the bottle, due to which the walls of the bag wrap around the cork and drag it out with them. This is such a strong gin!

To see how this happens, watch the video.

Wrong glass

On the eve of the experiment, ask the children what will happen if you turn a glass of water upside down. They will answer that the water will pour out. Tell them that this only happens with the “right” glasses. And you have the “wrong” glass from which water does not pour out.

To carry out the experiment you will need:

• glasses of water;
• paints (you can do without them, but this makes the experience more spectacular; it’s better to use acrylic paints– they give more saturated colors);
• paper.

Setting up the experiment

1. Pour water into glasses.
2. Add some color to it.
3. Wet the edges of the glasses with water and place a sheet of paper on top of them.
4. Press the paper firmly against the glass, holding it with your hand, and turn the glasses upside down.
5. Wait a moment until the paper sticks to the glass.
6. Slowly remove your hand.

Result and scientific explanation

Surely all children know that we are surrounded by air. Although we cannot see him, he, like everything around him, has weight. We feel the touch of air, for example, when the wind blows on us. There is a lot of air, and therefore it presses on the ground and everything around. This is called atmospheric pressure.

When we apply paper to a wet glass, it sticks to its walls due to the force of surface tension.

In an inverted glass, between its bottom (which is now at the top) and the surface of the water, a space is formed filled with air and water vapor. The force of gravity acts on the water, pulling it down. At the same time, the space between the bottom of the glass and the surface of the water increases. In conditions constant temperature the pressure in it decreases and becomes less than atmospheric. The total pressure of air and water on the paper from the inside is slightly less than the air pressure from the outside. That's why water doesn't pour out of the glass. However, after some time, the glass will lose its magical properties, and the water will still spill out. This is due to the evaporation of water, which increases the pressure inside the glass. When it becomes more atmospheric, the paper will fall off and the water will pour out. But you don’t have to bring it to this point. It will be more interesting this way.

You can watch the progress of the experiment in the video.

Gluttonous bottle

Ask your children if they like to eat. Do they like to eat? glass bottles? No? Don't they eat bottles? But they are wrong. They don’t eat ordinary bottles, but they don’t even mind having a snack with magic bottles.

To carry out the experiment you will need:

• boiled chicken egg;
• bottle (to enhance the effect, the bottle can be painted or embellished in some way, but so that children can see what is happening inside it);
• matches;
• paper.

Setting up the experiment

1. Peel off the shell boiled egg. Who eats eggs in a shell?
2. Set fire to a piece of paper.
3. Throw the burning paper into the bottle.
4. Place the egg on the neck of the bottle.

Result and scientific explanation

When we throw burning paper into a bottle, the air in it heats up and expands. By closing the neck with an egg, we prevent the flow of air, as a result of which the fire goes out. The air in the bottle cools and contracts. A pressure difference is created inside the bottle and outside, due to which the egg is sucked into the bottle.

That's all for now. However, over time I plan to add a few more experiments to the article. At home, you can, for example, conduct experiments with balloons. Therefore, if you are interested in this topic, add the site to your bookmarks or subscribe to the newsletter for updates. When I add something new, I will inform you about it by e-mail. It took me a lot of time to prepare this article, so please respect my work and when copying materials, be sure to include an active hyperlink to this page.

If you have ever conducted home experiments for children and organized a science show, write about your impressions in the comments and attach a photo. It will be interesting!