Report on the properties of snow and ice. Experiments "Ice and Snow"

Natalia Ilyina
Lesson summary “Properties of snow and ice”

Target: create conditions for the formation of ideas about properties of snow and ice.

Tasks:

1. Through practical research and modeling of natural objects and phenomena, derive property of snow and ice.

2. Develop creativity.

3. To cultivate in children a love for inanimate nature and its phenomena.

Equipment:

Symbols: « Snow» , "Ice", "White", "Loose", "Fragile", "Transparent", "Melting", "Water".

Form for ice.

Trays for snow and ice.

Hammer.

Projector.

Computer.

Envelope with riddles (the envelope is decorated with snowflakes).

Pencils.

Signal cards.

Material:

Snow, ice

Sheets of colored paper.

Sheets with part of a snowflake.

Preliminary work:

1. Observation of inanimate nature phenomena - frosts, snowstorms, snowfalls, blizzards, water freezing.

2. Looking at illustrations about winter, solving riddles about phenomena in inanimate nature, talking about the time of year.

Progress of the lesson.

Educator: Hello young nature lovers. I am glad to welcome you, where we will learn a lot of interesting and surprising things! An envelope arrived today. Guess from whom?

The teacher reads the riddle.

I wasn't raised

From the snow was blinded.

Instead of a nose cleverly

Inserted a carrot.

Eyes are coals,

Hands are bitches.

Cold, big - Who am I? -

Children: Snowman.

Slide show (snowman)

(Snowman says hello and asks riddles (educator)

All winter lies quietly,

And in the spring he will run away.

Children: Snow.

Not a gem, but glowing.

Children: Ice.

Snowman(educator)

Well done!

Educator: Guys, Snowman invites us to visit him and invites us to explore properties of snow and ice. Do you agree?

(children's answer)

Educator: Before we go on a visit, let’s put on winter clothes and felt boots. (Children imitate the movement) Let's hit the road. I'm ahead, and you're behind me, so here we are. Look how much snow and ice.

(On the tables there are transparent cups, a tray with snow and ice lumps, small scoops and hammer)

Practical work

Educator.

Place a piece in one glass ice, in the other - snow. Place them aside.

Look what color snow?

(children's answers)

(The teacher puts up a symbol with the image snow on easel)

Educator.

Place colored paper under the lump snow. Did you notice whether it was transparent or not?

(children's answers)

(The teacher places a symbol with an image on the easel)

Educator.

Is it easy to scatter a lump snow, let's try? What is he like?

(children's answer)

Educator.

What color is the ice?

(children's answer)

(the symbol with the image is displayed on the easel)

Place ice on colored paper. What did you notice?

(children's answer)

(the symbol with the image is displayed on the easel)

Look, I'll hit the ice. What will happen to the ice?

(children's answer)

(the symbol with the image is displayed on the easel)

Educator.

Let's take a look at snow and ice, which you put in the cups at the beginning of work. What happened to snow and ice? Why? What are they made of? snow and ice?

Conclusion:

Now guys, tell us everything you learned about snow and ice.

(children use symbols to talk about snow and ice)

-Snow is white, opaque, friable, turns into water under the influence of heat.

Ice is transparent, fragile, and turns into water under the influence of heat.

Educator.

Well done! Now let's rest.

Physical education minute

The sun warms the earth weakly, (Hands up and down)

The frost crackles at night,

(Hands on waist, bends to the sides)

In the snow woman's yard

(Hands on your belt, turn around yourself) The carrot nose turned white.

(children show nose)

Suddenly there was water in the river

motionless and firm

(Jumping in place)

The blizzard is angry

The snow is spinning,

(children spin around)

Sweeps everything around

Snow-white silver.

(Imitate hand movements)

Educator: And now Snowman invites us to a creative workshop.

(Children sit down)

Educator.

Where is ice found in winter?

(children's answer)

Can you see ice at home?

(children's answer)

How can you turn water into ice at home? (Put the water in the freezer.)

The teacher demonstrates the form for ice.

And when is it formed from water? snow?

Children: In winter. These are frozen droplets of water that fall from the sky.

Educator: Snowflakes form high above the ground in the clouds. When they accumulate in a cloud, cool, freeze, become heavy, they cannot stay in the sky and fall to the ground.

(Snowman thanks the children for their work and gives them snowflakes.)

Educator.

Look at them, but something is wrong here,

Snowman: I didn’t have time to finish drawing the snowflakes.

Educator: Guys need to help him! Take pencils and draw a snowflake.

(children finish drawing snowflakes)

Educator: Guys, well done, but it’s time for us to return to the group. We say goodbye To the snowman.

Educator. Did you like it class?

Who were we visiting?

(children's answer)

What were we doing there?

(children's answer)

And now, I propose to play a game of attention.

(The teacher distributes colored signal cards with the colors red and green, red means when answering (no, green when answering (Yes)

- Snow does it turn into water when it melts? (Yes)

If water freezes, does it turn into ice? (Yes)

- Snow is colorless? (No)

Is the ice transparent? (Yes)

Is the ice loose? (No)

- Snow white? (Yes)

Eremushkin Dmitry

This research work will be of interest to anyone who wants to know and study the properties of snow and ice: what is common between snow and ice, what are the significant differences, etc. The work can be used as additional material in physics lessons. The experiments described in this work can be carried out at home by any high school student. After reading the work, you can expand your horizons and learn about the amazing properties of snow and ice.

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V Municipal Scientific Research Conference

young researchers "Litvinov Readings"

"The Amazing Properties of Snow and Ice"

Scientific supervisor: Bizhova Tatyana Vasilievna

MBOU secondary school No. 135, 5 "A" class

Snezhinsk, 2015

Introduction………………………………………………………………………………… 3

Main part of the work

Chapter 1.

Research approaches………………………………………. 5

1.2 Practical study of the physical properties of snow and ice... 10

Chapter 2. The importance of snow and ice in human life and nature…………… 13

2.1 Snow and its role in the life of man and nature.

2.2 The role of ice in human life and nature.

Conclusion ……………………………………………………………………. 15

Literature……………………………………………………………………………….. 16

Introduction

Under blue skies
Magnificent carpets,

Glistening in the sun, the snow lies;
The transparent forest alone turns black,
And the spruce turns green through the frost,
And the river glitters under the ice.
A. S. Pushkin.

The sorceress, nature, has prepared many miracles. Every season is interesting and beautiful in its own way. Everyone has their own secrets. But the most magical time of the year is winter.

There is snow in the winter. And snow is the most important miracle. With the arrival of winter, the temperature drops, snow falls - and the dull black field turns, as if by magic, into a magnificent white carpet sparkling in the sun. The forest thickets are transformed, spruce trees and house roofs are dressed in white clothes. The water in reservoirs freezes. Ice binds rivers, lakes, and ponds.

Truly snow is one of the most amazing natural phenomena. Thus, the German astronomer Johannes Kepler found out that almost all snowflakes are six-pointed crystals. The French philosopher Rene Descartes was engaged not only in philosophical reasoning, but also in observations in the field of natural sciences. So, he published the first sketches of snowflakes. In his sketches you can even see twelve- and eighteen-pointed crystals, which are very rare in nature.

Snow and ice are studied by the same science - glaciology, the science of ice, which originated at the end of the 18th century in the Alpine mountains. The problem of snow and ice is interesting not only for astronomers and physicists, but also no less attractive for the poets S.A. Yesenin, A.A Fet and many others.

Everything, everything is white! Eyes can't tell the difference
How the snow mixed with the plum color...
Where is the snow? Where is the color?
And only the aroma
Will tell people: plum or not.

S.G. Ostrovoy once said that snow fascinates, attracts people to itself, like some kind of magic magnet. The poet tried to express this in a poem that he dedicated to snow:

And I kept stroking the snow with my hand,
And he was shining with stars...
There is no such melancholy in the world,
Which snow would not heal.
He's all like music. He is the message.
His recklessness is boundless.
Oh, this snow... It’s not for nothing that it contains

There's always some kind of mystery.

It is difficult to imagine forests and plains without snow, without its charm. He, fluffy, sparkling, gives us joy, teaches us beauty from childhood.And the snow itself! What could be more fickle, more changeable and mysterious? Here he is - and suddenly he disappears, melts. Now it is white and fluffy, and tomorrow it has settled down, become gray and wet. Or in other words - yesterday it was fluffy and soft, but now it has become hard and dense. Let it sit for a while and turn into ice. He was born above the ground in the form of almost weightless snowflakes, but some time passed - and he floated down the river like ice floes.

The amazing variability of snow sometimes makes it difficult to realize and understand what is snow and what is ice? Therefore, I was especially interested in the question, what properties do they have?

Hypothesis: It can be assumed that snow and ice are frozen water. And find out their physical properties.

Purpose of the study: Identify and study the physical properties of snow and ice through practical experiments.

Object of study: Snow and ice.

Subject of study:Physical properties of snow and ice.

In accordance with the problem, subject and purpose of the study, the following tasks were set:

• Study and analyze scientific and fiction literature on the problem.
• Get acquainted with the physical properties of snow and ice.

In solving the assigned problems, the following research methods were used: analysis of scientific and fiction literature, direct and indirect observations, conducting experiments, analyzing the results obtained.

The research took place in several stages:

Stage 1: a walk in the winter forest, studying literature on the problem.

Stage 2: conducting practical experiments.

Stage 3: analysis and generalization of experimental work, preparation of research work.

Chapter 1. Physical properties of snow and ice

Scientific theoretical approaches to the problem

Snow is solid atmospheric precipitation consisting of ice crystals of various shapes - snowflakes, mainly hexagonal plates and six-rayed stars; falls from clouds at air temperatures below 0 °C. The most wonderful feature of our planet. It is formed on all continents in huge quantities. Every year, snow covers up to 130 million square kilometers - a quarter of the entire surface of the Earth, including the oceans.

Snow is amazingly variable. Physical properties such as density, thermal conductivity, heat capacity, porosity, humidity, speed of sound, etc. for snow fundamentally cannot be maintained for a long time and remain unchanged. Everything changes and transforms, right down to the structure, shape and size of snowflakes, their connectivity. Suffice it to say that the density of snow can change. With a further increase in density, snow turns into ice, which is fundamentally different in properties from its predecessor, says Academician A.K. Dunin.

The density of forest snow differs from snow on the plain. In the Siberian taiga, where there are no winter thaws, the average density of a meter thick snow in some places does not exceed 0.10 g/cm3. In the steppes and tundra, snowstorms greatly compact the snow; there the density is 2.4 times greater. In the Far North, the snow can be so hard that when an ax hits it, it rings as if struck by iron. Such snow polishes the soil surface and injures plants. And in Antarctica, a 3-4 meter layer of snow that falls becomes so dense in a few days that it can hardly be ripped open by the heavy knife of a powerful bulldozer.

Very complex processes of mass and heat transfer constantly occur in the snow cover. The processes of evaporation and crystallization are especially interesting. It’s easier to describe them using the example of a single snowflake. How is it formed?

Initially, embryonic ice crystals appear around crystallization nuclei (tiny foreign particles). Moving up and down, they enter a layer of air with supercooled water droplets. Here, the future snowflake begins to rapidly increase in size due to sublimation (the transition of water vapor contained in the air into snow). At the same time, the convex areas of the snowflake grow faster. Thus, a six-rayed star grows from the initially hexagonal plate. Many factors influence the formation and growth of snowflakes, which is why the variety of their shapes is so great. If a snowflake collides with supercooled small droplets on its path, then it becomes simpler in shape. If it collides with a large drop, it can turn into a hailstone. At low temperatures and strong winds, snowflakes collide in the air, crumble and fall to the ground in the form of debris. Sometimes, if the frost is about 40°C, ice crystals that form in the atmosphere fall out in the form of “diamond dust.”

The lifespan of a free-floating snowflake is tens of minutes. Let the snow cloud layer be at a height of 2 km above the earth's surface. The average falling speed of snowflakes is 1 m/s. This means that a snowflake falls from cloud to ground within 2000 s, or 33 min. At low temperatures, snow has time to fall to the ground and form a snow cover. At high temperatures and a large deficit of air humidity, snowflakes will evaporate without reaching the ground, and in this case, “there are clouds, but no snow.” In the mountains, the distance from the clouds to the ground is much less than on the plains. This is one of the main reasons that much more snow falls in mountainous areas than in lowland areas.

If a snowflake falls on your hand, you won’t feel it. After all, it only weighs about a milligram!

But the “downy” blanket of snow on the surface of the Earth becomes like heavy weights that can affect the speed of the Earth’s rotation. During the period of least snow on the Earth, 8.7 percent of the entire surface of the planet is covered with snow (7 percent in the southern hemisphere and 1.7 percent in the northern), and such a cover weighs 7,400 billion tons. By the end of winter in the northern hemisphere, the mass of seasonal snow reaches 13,500 billion tons.

Snow is like a huge mirror, reflecting almost 90 percent of the sun's radiant energy into space. No other natural body has such a high reflectivity. A blanket of snow, which is considered warm and which saves plants and animals from frost, significantly contributes to the cooling of the planet on a global scale: it isolates vast areas from the sun’s rays for a long time.

Snow creaks only in frost, and the pitch of its creaking changes depending on the air temperature - the stronger the frost, the higher the pitch of the creaking. There are people who can estimate air temperature by auditory changes in the nature of the creaking of snow. The creaking of snow is nothing more than the noise of tiny snow crystals being crushed. Individually, each of them is so small that when it breaks, it produces a sound inaudible to the human ear. But when billions of such “voices” are summed up, a very clear creak appears. Acoustic measurements have shown that there are two maxima in the spectrum of snow squeaking - in the range of 250...400 Hz and 1000...1600 Hz. In most cases, the low-frequency maximum is several decibels higher than the high-frequency maximum. If the air temperature is more than minus 6°C, the high-frequency maximum disappears. Increasing frosts make ice crystals harder and more fragile. With each step, the ice needles break, and the acoustic spectrum of the squeak shifts to the high frequency region. With a change in temperature from minus 8°C to minus 20°C, the sound intensity of creaking snow increases by 1 decibel.

The life of mammals often depends on the type of snow in the forest - fluffy, deep or covered with crust. Specific pressure on snow—the weight of an animal’s body per unit area of ​​its foot—is what determines the “relationship of forces” in a snow-covered field or forest. Thus, for hares, the load on snow usually does not exceed 30 grams per square meter. cm of the supporting area of ​​the limbs, for a fox - 40..-. 50g, for a wolf - about 10 g, for ungulates - from 200 to 970g. Predators have a significantly lower trail load than their prey. Therefore, if the snow is covered with crust, the ungulates get stuck deep in the snow, and predators run easily, almost without falling through. But if the snow is fluffy and deep, then the ungulates have an advantage. With a snow depth of 50 cm, the wolf cannot catch up with the deer. And at 60 cm, the wolf can barely make his way through the snowdrifts. For a person, depending on the weight and type of ski, the load on the snow varies within 10-25 g per sq. cm. This means that any hunter can move freely in the snow. To slide on snow - to move on a sleigh - you need to spend 10 times less energy than when moving on wheels. With the pressure and friction of the runners of a sled or ski, the surface particles of the snow cover melt, and the resulting film of water serves as a lubricant. Therefore, “slipperiness” depends on the temperature of the snow and the speed of movement. Friction is minimal when sliding on dry snow at temperatures close to 0°C. If the snow becomes wet, friction begins to increase in proportion to the moisture. At temperatures below minus 25°C, the resistance of snow to sliding at low speeds approaches the value of the resistance to sliding on dry sand. An increase in sliding speed leads to a decrease in friction. High running speed seems to help glide and thereby contribute to even greater speed. When stopped, the water film under the skid freezes and ice forms. The longer you stop, the more you freeze. Accordingly, the effort required to move again increases. During a short stop (for example, at the end of a ski slide, before the next push), it is minimal. If the strength of freezing between the surface of the ski and the snow turns out to be greater than the resistance of the snow to the shear of the ski, then a phenomenon familiar to many occurs - snow sticks to the skis. And the more often you stop to rest, the heavier the skis become. A special lubricant can help here, reducing the freezing strength and improving sliding.

Thus, the physical properties of snow and ice are fraught with many mysteries. Solving them is not only an interesting problem, but is also directly related to the moisture cycle on planet Earth.

1.2 Practical study of the physical properties of snow and ice

It can be assumed that such widespread materials in nature as snow and ice have been studied quite well and their properties are generally known. What secrets can they still keep? I decided, unexpectedly for myself, to enter an unknown kingdom, onto paths of knowledge untrodden by me. That's what came out of it. I will give examples of my wanderings along one of these seemingly clear paths.

Target: identify the properties of snow and ice experimentally.

Experience No. 1. I took some fresh powdered snow from the street and put it in a measuring cup. At home, I lowered a thermometer into a glass of snow and monitored its readings. Recorded temperature data until the snow completely melted.

Using these data, I made a table and built a graph that shows how quickly the snow melts and how the temperature changes. On the graph, I marked the thermometer readings on the vertical axis (ordinate axis), and the time interval on the horizontal axis (abscissa axis).

When the snow had completely melted, I noted the water level. I saw that the level had changed. The volume of water is less (80 ml) than the volume of snow (500 ml). The volume changed by 6.25 times.

So why is the volume of water less than the volume of melted snow?

The snow simply changed its state of aggregation. And that is why it “decreased.” Snowflakes cannot press tightly against one another; there is always air between them. That's why they take up a lot of space.

And when these same snowflakes melt, the molecules of which they are composed lose their rigid structure. Now they can get closer to each other so that there is no gap between them. And therefore they take up less space.

Experience No. 2. I’ll take four plastic disposable cups, pour water into them and put them in the refrigerator to freeze. When the water completely turns into ice, I take the cups out of the refrigerator. It can be seen that the ice has risen in a tubercle. Water does not freeze evenly. At first, ice appears at the walls of the glass, gradually filling the entire glass. In water, molecules move randomly, so it takes the shape of the glass into which it is poured. Ice has a clear crystalline structure, and the distances between ice molecules are greater than between water molecules, so ice takes up more space than water, that is, it expands.
Therefore, the volume of ice is greater than the water from which it was made.

Experience No. 3

Now I will watch how the ice defrosts under different conditions. You need to prepare 4 identical plates and get ice from each glass.

*Put the first piece of ice in a dry bowl;

*The second - in a bowl filled with hot water;

*Third - in a bowl of water at room temperature;

* In the fourth bowl I will put a piece of ice, after wrapping it with a piece of cotton wool.

Watching the ice melt in each bowl.

Ice will melt fastest in a bowl of hot water, then in a bowl filled with cold water. Please note that ice does not sink in water, which means it is lighter than water. Only a small part of the ice floe protrudes above the water, but most of it is still covered with water. A piece placed in a dry container will melt more slowly due to the fact that the thermal conductivity properties of water are better than the thermal conductivity properties of air. But ice wrapped in cotton wool, oddly enough, will take the longest to melt, since the insulation of the wool does not allow it to interact with the surrounding warm air. Another interesting feature is related to the melting of ice from fresh and salt water. If you freeze cups of fresh water and a salt water solution, then place them in the same conditions to defrost, you will find that salted ice will melt slightly faster than unsalted ice.

Observation #1. Let's dig out the snow with a shovel. We see small sprouts of grass. These are winter wheat varieties. Many animals spend the winter in the snow and hide from the cold: mice, bears, chipmunks, hedgehogs. What do fishermen do on the river in winter? Why doesn't every living thing freeze under the ice? It turns out that the temperature under the ice is above zero. Snow is needed by plants, roots, seeds; it does not provide warmth, but, like ice, it retains heat.
Conclusion : snow and ice retain heat, and therefore are of great importance for the life of plants and animals.

Observation #2 . Playing snowballs, building snow towns, fortresses, skiing, sledding, skating are winter entertainment for people.

Conclusion : The snow is loose and the ice is slippery.

Chapter 2. The importance of snow and ice in the life of man and nature

2.1 Snow and its role in human life and nature

M We love snow not only because it gives us magnificent winter landscapes. There are many rational reasons for our love for snow. “Snow in the fields means bread in the bins,” “Winter without snow means summer without bread,” old Russian proverbs rightly say.Snow cover is a huge supply of moisture, much needed by the fields, and at the same time it is a kind of giant blanket that protects the surface of the earth from cold winds. Academician B.I. Vernadsky emphasized that snow cover is “not just a warm cover for winter crops, it is a life-giving cover,” and in the spring it provides melt water saturated with oxygen. It is known that the amount of nitrogen compounds in the soil in summer is proportional to the height of the melted snow cover. It is not without reason that snow reclamation is considered today as one of the most important conditions for obtaining high and sustainable yields.

Snow reserves significantly affect water levels in rivers and determine climate changes over large areas.

In addition, snow is a good building material for various buildings in the north - from igloos (Eskimo dwellings) to large warehouses. There is the world's largest hotel, made entirely of ice and snow, located in Swedish Lapland, 200 kilometers from the Arctic Circle. Having modestly started with a single room, the hotel has grown to 5 thousand square meters in 15 years. 30 thousand tons of snow and 4 thousand tons of ice welcome 37 thousand guests per season. The climate inside the hotel varies depending on the temperature outside - ranging from 4 to 9 degrees Celsius below zero. And outside it could easily be minus 40. Hotel guests sleep in warm sleeping bags on special beds made of snow and ice, on reindeer skins. It serves as the basis for winter roads and even airfields.

Thanks to snow, every year we admire fabulous winter landscapes, play snowballs, build snow towns, fortresses, ski and sled. A wonderful New Year holiday comes to us covered in snow.

2.2. Ice in the life of man and nature

The importance of ice is difficult to underestimate. Ice has a great influence on the living conditions of plants and animals, and on various types of human economic activity. Covering the water from above, ice plays in nature the role of a kind of floating screen, protecting rivers and reservoirs from further freezing and preserving life in the underwater world. If the density of water increased as it froze, the ice would be heavier than the water and begin to sink, which would lead to the death of all living creatures in rivers, lakes and oceans, which would freeze completely, turning into blocks of ice, and the Earth would become an ice desert, which is inevitable would lead to the death of all living things.

Ice can cause a number of natural disasters with harmful and destructive consequences - icing of aircraft, ships, structures, road surfaces and soil, hail, blizzards and snow drifts, river congestion with floods, ice avalanches, etc. Prediction, detection, prevention of harmful phenomena, combating them and using ice for various purposes (snow retention, construction of ice crossings, isothermal warehouses, lining storage facilities, ice filling of mines, etc.) are the subject of a number of sections of hydrometeorological and engineering knowledge (ice engineering, snow engineering, permafrost engineering, etc. ), activities of special services (ice reconnaissance, icebreaker transport, snow removal equipment, artificial avalanches, etc.).

Natural ice is used for storing and cooling food products, biological and medical products, for which it is specially produced and prepared.

In Rus' they rode on “ice sleds”. Ice circles were prepared and a place for a seat was cut out in them. They put straw and hay there. A hole was made in the front of the ice cube for the rope. The ice cube was carefully leveled from below. Our great-grandmothers and great-grandfathers rode on ice like these. Craftsmen make real works of art from ice: ice carriages, palaces, castles.

Conclusion

As a result of our experiments and observations, we confirmed the initial hypothesis, according to which snow and ice are frozen water and their relationship is proven by physical properties. Snow and ice are of great importance in the life of wildlife and humans. Snow and ice are fun for kids and adults.

Literature

1. Great schoolchild encyclopedia. "Planet Earth". "Publishing house Rosman-Press", 2001.- 657 pp.: A. Yu Biryukova.

1. A. Yu Biryukova. Fauna of our Motherland. Manual for primary school teachers, Moscow, Education, 1985.-205s: V.P. Gerasimov

1. Dictionary of the Russian language, ed. N.Yu. Shvedova, Moscow “Russian language”. 1989
2. Encyclopedia for a young scholar about everything from A to Z. Moscow, “Swallowtail”. 2008
3. Non-standard integrated lessons for the course “The World around us” - M: VAKO, 2004, N.T. Brykina, O.E. Zhirenko.

WikiHow works like a wiki, which means that many of our articles are written by multiple authors. This article was produced by 37 people, including anonymously, to edit and improve it.

Winter outdoor activities, including snowshoeing, snowmobiling, ice fishing (with or without a vehicle), skiing, ice skating, and playing on ice can be dangerous if you cannot determine whether the ice is strong enough to support load. There are various ways to assess the potential reliability of ice cover - you can observe the color of the ice and examine its thickness, as well as pay attention to external factors such as temperature, local conditions and features. However, it is impossible to completely eliminate risk during sporting events. If in doubt, do not go on the ice; and even more so, you shouldn’t do this too early or too late out of season.

Steps

Please note that ice is never completely safe. Weather conditions and subtle or unknown factors can suddenly turn seemingly safe ice into deadly ice. Take all possible precautions to prevent accidents and ensure that rescue measures can be taken immediately if something goes wrong.

Develop an emergency rescue plan. Tell your friends where you are going. If something unexpected happens while you're exploring ice conditions or having fun, you should have a plan in place that will get you to a safe place where you can get immediate help.

• Advice for beginners: You should dress very warmly according to the season. Do not neglect water rescue equipment, at least a life jacket, especially if you are testing the ice for strength or going on a trip in a snowmobile. Keep an ice ax with you, which can help you get out if you get caught in a hole. Never go alone, take one or two friends with you. Let your friends know where you and your friends are and when you expect to return home. This is not a case where you can be carefree and act spontaneously.
• Carry a spare set of warm, dry clothes in a waterproof duffel bag. This way, you can reduce the risk of hypothermia by immediately changing wet clothes. Other useful items in a rescue kit include a blanket, hand and foot warmers, thick socks, extra wool caps, candles and matches. Have all of these things ready in case you engage in any winter sports, such as ice skating. For more information, see the "Things You'll Need" section.

1. Understand that the strength of ice is determined by a number of factors, not just one. Its reliability can be judged by assessing the combination of the following indicators:

   • Appearance of ice - its color, structure and features
   • Ice thickness – recommended thickness is determined for certain types of activities, which can be read below
   • Temperature maximum over a certain time and during the day
   • Snow cover
   • Depth of water under ice
   • Pond size
   • Chemical composition of water - salty or fresh
   • Weather changes in the area
   • Length of ice cover

2. Choose places where the ice is regularly tested for strength by the relevant services. Such services may exist at resorts, clubs, national parks or as part of government agencies. They must take measurements at least daily. Ask the employees of these services about the results of the check, this will protect yourself. They usually use high-quality measuring instruments and have access to research, and they also know a lot about ice and are well prepared for emergency situations. You will save yourself from risky testing of ice surface strength and will feel more confident. However, this does not mean that you can forget about precautions.

   Talk to the locals. If you are a newcomer, you should not show any arrogance. Go to the grocery store, fishing store, or sporting goods store and strike up a conversation, or stop by the police station or fire station and ask about dangerous and safe places in the area. It is better for them to help you now than to help you out of trouble later.

3. Inspect the ice. Look closely to see if there are any cracks, breaks, suspicious areas or uneven surfaces, and determine its color(s). You can only rely on your own vision . This quick glance will help you decide whether to continue your research.

   • If you have the following signs, you should refrain from any further attempts to go on the ice:
     • Water submerging the ice edge or near it
     • Springs flowing under the ice in ponds and lakes fed by springs.
     • The presence of a source or tributary of an ice-covered body of water
     • Cracks, faults or holes
     • Ice that apparently thawed and then froze again
     • Uneven surfaces you haven't noticed before - such as ridges of ice caused by currents or winds
   • Remember this song: "Thick and blue, tried and true; thin and fragile - the path is too risky."

4. You need to understand the meaning of a particular color of ice. But while this is a very useful indicator, you shouldn't rely on color alone. For example, ice of any color that is exposed to flowing water from below will be more brittle than ice that is not so exposed. Typically, based on the color spectrum of ice, you can draw the following conclusions:

   • Light gray to black is melted ice that sometimes forms even when the air temperature is below 32°F (0°C). Unsafe: Due to insufficient density, it cannot support the load - stay away.
   • White to dull, opaque, water-soaked snow freezes on top of the ice, forming another thin layer of ice on top. This ice is too porous and may have air pockets inside it, so it is often brittle.
   • From blue to transparent - ice is high density, very durable, the safest, if, of course, it is thick enough. Don't risk it if it's less than 4 inches (10 cm) thick.
   • Motley and loose ice, also called “rotten” - not so much because of its color, but because of its structure. This is melted ice. It is treacherously deceptive - it is very possible that it has melted in the middle or at the bottom, although it seems thick on top. It is most often found in the spring and can have a brownish tint due to plant pigments, dirt and other natural materials rising to the surface during the thaw. You won't take a single step.

5. Check the thickness of the ice. If you have already completed the inspection and it seems to you that everything is in order, you need to make sure of this by examining the thickness of the ice.

   • Conduct research in the presence of at least one friend (mutual assistance system). Wear a rescue suit or other flotation device and use ropes so that your friend can pull you out if necessary.
   • Only go out on the ice if the ice edge is strong enough. If it is loose or cracked, for your own safety it is not worth continuing, because the coastal ice edge is the most fragile.
   • To measure the thickness of the ice, make a small hole with a hatchet or use a hand auger.
   • Study the safe ice thickness indicators. There are recommended criteria that you need to keep in mind for any activity you undertake on the ice. (Keep in mind that their compliance recommended, but does not in itself guarantee your safety.) Ice becomes “safe” at approximately 4 to 6 inches (10 to 15 cm) thick. Don't even think about going out on ice that is 3 inches (7.5 cm) thick or less. However, even with a thickness of 9 - 10 inches (22.5 - 25 cm), the ice can harbor hidden threats, such as fast currents that tirelessly erode the ice from below. In this case, even thick ice can crack at any moment.
   • Under normal conditions, the rules for safe ice thickness are as follows:
     • 3 inches (7 cm) (young ice) - "KEEP AWAY
     • 4" (10 cm) - Suitable for ice fishing, ski touring and hiking (supports approximately 200 lbs (80 kg) weight)
     • 5" (12 cm) - Suitable for single snowmobiles and snowmobiles (supports approximately 800 lbs (320 kg))
     • 8 - 12 inches (20 - 30 cm) - supports a single vehicle or group of people (approximately 1500 - 2000 lbs (600-800kg))
     • 12 - 15 inches (30 - 38 cm) - Supports the weight of a light-duty pickup truck or RV
   • These norms are considered generally accepted.

6. Keep in mind that ice thickness is not the same everywhere, even on the same body of water. The reliability of the ice coating is determined not only by color and thickness, but also by a number of other indicators. Consider also:

   • The nature of the body of water: is it a pond, lake or river, and is there a noticeable current under the ice? Does the body of water have tributaries or a source? This may be a cause for concern.
   • Composition of water: is it salty or fresh? Sea ice is usually less durable and, given the same thickness, may not support the same weight as freshwater ice. For more information regarding the exact criteria, see the external links below.
   • Temperature maximum and time of year: the temperature is constantly changing. Consider the microclimate in the area. Winter ice is much stronger than spring ice; the latter quickly melts and thins out under the rays of the sun.
   • Size and depth of the reservoir: freeze-up on large bodies of water takes much longer than on small ones.
   • Availability of snow cover: snow is a natural heat insulator; Under snow, the ice is usually thinner and less durable.
   • Weight Size: How much pressure are you putting on the ice? Should it only support you or your vehicle as well? A human body and a snowmobile with the same body on it have very different weight distribution parameters.

7. If you have even the slightest doubt, find an alternative. Skating enthusiasts can always use the ice skating rink or the controlled part of the lake; Skiers and snowmobile drivers may be advised to stick to inland roads; It is also better for pedestrians to avoid the ice. Either way, they all need to carry a survival kit no matter where they plan to go or how long they plan to be on the road.

   Hints

   • Remember that well-worn ice roads and crossings do not make the ice stronger. Routes should be changed regularly.
   • If you NEED to cross a body of water on ice, the best way to do this is to get down on all fours and move with your arms and legs spread wide. Try to move like a lizard, distributing your body weight evenly. Bringing a long board or pole with you is a great idea. If the ice starts to crack - and you sometimes get a second warning - place the pole on the ice and use it to distribute your weight over a larger area.
   • When traveling, treat other people responsibly. If you are a leader (at a school or sports camp, etc.), make sure that your students do not leave the territory you have designated and immediately return them back. Ensure that sufficient warning signs are installed so that skaters, etc., cannot make an irreparable mistake and go beyond the safe zone. It is also necessary that a person trained in first aid with a rescue kit be present nearby.
   • Dog sleds on ice are a little safer because dogs can sense cracks forming. Still, don't do anything risky and be just as prepared for accidents as you are with other winter sports.
   • If you must skate on thin ice (literally), make sure the water is shallow (ie 2 - 3 feet (60 - 90cm)). If you fall through, you will get wet and freeze, but you will be able to get ashore, despite the unpleasant sensations. Of course, this is unacceptable for children.
   • It is safer for two people to cross unreliable ice on opposite sides of a canoe being pushed on the ice. Don't forget the oars. You may need them on crossings.

   Warnings

   • This article applies to people living in cold climates such as Canada, the northern United States, and Russia. If your country or area does not have normal winter conditions, be aware that ice will be unsafe at any time of the year and do not even think about doing any of the above without the advice of professionals, preferably local government agencies authorized to make such recommendations.
   • Never drink alcohol while engaging in winter sports - wait until you return to your home or country house. Alcohol can cause errors when operating a snowmobile, increase reaction time, and impair the ability to act quickly in an emergency. Alcohol does not help fight the cold; it actually increases heat loss and can lead to hypothermia.
   • Never go on the ice unless it has been checked by professionals and found to be safe. But even when this condition is met, drivers sometimes fall through the ice. If you must drive, be alert - don't speed, roll down your windows (turn the heater up high if it makes you uncomfortable) and unfasten your seat belts.
     • Make sure you know how to get out of a sinking car and you have discussed rescue procedures with all passengers.
     • Drive slowly on ice, especially when approaching the shore. Why? The weight of the vehicle - be it a snowmobile, car or truck - presses down on the ice from above. As you advance, this causes a small but sensitive wave vibration that spreads across the ice in front of you. This wave may bounce off the shore as you approach. Depending on your weight and speed, this could cause an ice break.
     • Do not take children on trips on ice roads unless you simply have no other means of providing the necessary emergency care. You won't have time to think about them when you get out of your sinking car.
   • Snowmobile drivers should not drive at high speed - if they cannot see what's ahead, they will most likely end up in a hole because they will not be able to brake in time. In addition, on slippery ice, it may simply be impossible to sharply drive around a suddenly appeared wormwood. It is more likely that you will get into a skid, as a result of which you will end up in the water. Better stay on the shore.
   • Never skate, play or travel on ice, on foot, on skis or in a snowmobile, at night. You won't be able to see anything if an accident occurs and you probably won't get help.
   • Don't assume that a sudden cold snap makes the ice safer. In fact, in this case the ice becomes brittle and brittle even sooner than during a brief thaw. Always check.
   • Just because the ice in the area you surveyed seems safe does not mean that it will be so somewhere else in the same body of water. If you are going to go beyond the area you have explored, you must again conduct a check or define the boundaries of the safety zone.
   • When driving on a ski or snowmobile trail, do not use ice-covered streams, rivers, ponds or lakes as shortcuts unless they are recognized as such by local authorities and surveyed daily. People often take shortcuts at the end of the day, when athletes are tired and want to get home quickly and it is getting dark; Mostly at this time accidents happen, simply because you are tired. In addition, the influence of daytime heat is felt towards the end of the day, when the ice becomes least strong.

Today we will talk about the properties of snow and ice. It is worth clarifying that ice is formed not only from water. In addition to water ice, there is ammonia and methane ice. Not long ago, scientists invented dry ice. Its properties are unique, we will consider them a little later. It is formed when carbon dioxide freezes. Dry ice got its name due to the fact that when it melts it does not leave puddles. The carbon dioxide contained in it immediately evaporates into the air from its frozen state.

Ice definition

First of all, let's take a closer look at ice, which is obtained from water. There is a regular crystal lattice inside it. Ice is a common natural mineral produced when water freezes. One molecule of this liquid binds to four nearby ones. Scientists have noticed that such an internal structure is inherent in various precious stones and even minerals. For example, diamond, tourmaline, quartz, corundum, beryl and others have this structure. The molecules are held at a distance by a crystal lattice. These properties of water and ice indicate that the density of such ice will be less than the density of the water due to which it was formed. Therefore, ice floats on the surface of the water and does not sink in it.

Millions of square kilometers of ice

Do you know how much ice there is on our planet? According to recent research by scientists, there are approximately 30 million square kilometers of frozen water on planet Earth. As you may have guessed, the bulk of this natural mineral is found on the polar ice caps. In some places the thickness of the ice cover reaches 4 km.

How to get ice

Making ice is not difficult at all. This process is not difficult and does not require any special skills. This requires low water temperature. This is the only constant condition for the ice formation process. Water will freeze when your thermometer shows a temperature below 0 degrees Celsius. The crystallization process begins in water due to low temperatures. Its molecules are built into an interesting ordered structure. This process is called the formation of a crystal lattice. It is the same in the ocean, in a puddle, and even in the freezer.

Research into the freezing process

Conducting research on the topic of water freezing, scientists came to the conclusion that the crystal lattice is built in the upper layers of water. Microscopic ice sticks begin to form on the surface. A little later they freeze together. Thanks to this, a thin film is formed on the surface of the water. Large bodies of water take much longer to freeze compared to still water. This is due to the fact that the wind ripples and ripples the surface of a lake, pond or river.

Ice pancakes

Scientists made another observation. If excitement continues at low temperatures, then the thinnest films are collected into pancakes with a diameter of about 30 cm. Then they freeze into one layer, the thickness of which is at least 10 cm. A new layer of ice freezes on top and bottom of the ice pancakes. This creates a thick and durable ice cover. Its strength depends on the type: the most transparent ice will be several times stronger than white ice. Environmentalists have noticed that 5-centimeter ice can support the weight of an adult. A layer of 10 cm can withstand a passenger car, but it should be remembered that going out on the ice in autumn and spring is very dangerous.

Properties of snow and ice

Physicists and chemists have long studied the properties of ice and water. The most famous and also important property of ice for humans is its ability to easily melt even at zero temperature. But other physical properties of ice are also important for science:

• ice is transparent, so it transmits sunlight well;
• colorlessness - ice has no color, but it can be easily colored using color additives;
• hardness - ice masses perfectly retain their shape without any outer shells;
• fluidity is a particular property of ice, inherent in the mineral only in some cases;
• fragility - a piece of ice can be easily split without much effort;
• cleavage - ice breaks easily in those places where it is fused along a crystallographic line.

Ice: displacement and purity properties

Ice has a high degree of purity in its composition, since the crystal lattice does not leave free space for various foreign molecules. When water freezes, it displaces various impurities that were once dissolved in it. In the same way, you can get purified water at home.

But some substances can slow down the freezing process of water. For example, salt in sea water. Ice in the sea only forms at very low temperatures. Surprisingly, the process of freezing water every year is capable of maintaining self-purification of various impurities for many millions of years in a row.

The secrets of dry ice

The peculiarity of this ice is that it contains carbon in its composition. Such ice forms only at a temperature of -78 degrees, but it melts already at -50 degrees. Dry ice, the properties of which allow you to skip the stage of liquids, immediately produces steam when heated. Dry ice, like its counterpart water ice, has no odor.

Do you know where dry ice is used? Due to its properties, this mineral is used when transporting food and medicine over long distances. And the granules of this ice can extinguish the fire of gasoline. Also, when dry ice melts, it forms a thick fog, which is why it is used on film sets to create special effects. In addition to all of the above, you can take dry ice with you on hikes and in the forest. After all, when it melts, it repels mosquitoes, various pests and rodents.

As for the properties of snow, we can observe this amazing beauty every winter. After all, every snowflake has the shape of a hexagon - this is unchanged. But besides the hexagonal shape, snowflakes can look different. The formation of each of them is influenced by air humidity, atmospheric pressure and other natural factors.

The properties of water, snow, and ice are amazing. It is important to know a few more properties of water. For example, it is able to take the shape of the vessel into which it is poured. When water freezes, it expands and also has memory. It is able to remember the surrounding energy, and when it freezes, it “resets” the information that it has absorbed.

We looked at the natural mineral - ice: properties and its qualities. Continue to study science, it is very important and useful!

Lesson "Properties of snow and ice."

Subject: environment

Class: 3 "A"

* introduce students to some of the physical properties of snow and ice;

* form the idea that snow and ice are frozen water, and that in nature they are observed in different forms;

* introduce scientists who have conquered the Arctic;

* develop imagination, observation;

* cultivate love for native nature;

* Introduce Russian craft - Vologda lace;

Equipment:

* snow and ice,

* glasses, saucers,

* colored paper,

* presentation,

* set for a model of the water cycle in nature,

* dolls – Snowflake and Ice.

* cards 1, 2, 3.

During the classes:

I. Organizing time

2. - Guess who

Gray-haired Mistress:

The featherbeds will shake,

Above the world of fluff? (winter)

Today we will continue to talk about winter, about winter phenomena in inanimate nature. Presentation. Slide 1 (Winter landscape) (1 min)

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3. Checking homework

What observations of nature have you made? (observation diary).

What has changed over the past days of December? (1 min)

Water occurs naturally in:

1) 2 states

2) 3 states

3) 4 states.

Snow and ice are found in:

1) Liquid state

2) Gaseous state

3) solid state.

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P. 39 of the textbook - questions on the topic. (3 min)

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Snowflake 1:

In the sky was born from a drop of water

A carved star of marvelous beauty.

I’ll fly from the sky with a sparkling lens,

I'll sit down and melt if I want.

Ice 2:

And I was also a little clean.

And when she froze, she seemed to freeze.

I’m also sparkly and not big.

I am a radiant piece of ice, I am your sister!!!

Snowflake 3:

But no!!

I am made of the sun, silver!!

You are muddy water!

Just a mess!!

Me too, twin.

Ice 4:

Come to your senses!! That's right!!

After all, I am your sister!!

Guys, do you want to help Ice and Snowflake?

What are they asking you to do?

Prove that they are sisters.

To prove the relationship between snow and ice, we need to study their properties. And experiments will help us with this. (2 minutes)

II. New material.

1) Practical work.

Put a piece of ice in one glass and a lump of snow in the other. Let's put them aside for a while

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What color is the ice? Find a square that matches the color of the ice. Let us conclude: ice has no color, i.e. colorless.

Take a saucer with colored paper. Let's put a thin layer of snow on it, and next to it - a plate of ice. Compare. What did you notice? What can we call this property of ice and snow?

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Children. Snow is loose, ice is dense.

Let us establish one more property of ice. (The teacher crushes the ice. The ice breaks)

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Presentation. Slide 4. (polar station, Ladoga) (3 min)

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Teacher. Let's now look at the snow and ice that we put in the glasses at the beginning of our work. What happened to the snow and ice? Why? So what are snow and ice?

Children. Snow and ice are frozen water.

Teacher. Have we proven that Snowflake and Iceflake are sisters?

Children. Yes, they proved it. (2 minutes)

6. Generalization. Children have cards with tasks.

Snow and ice are water in ____________ state.

The color of snow is ___________, and the color of ice is _______________.

Opaque and _____________ transparent.

Snowflakes are formed from __________________ ___________.

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7. Physical exercise. Music.

We are snowflakes, we are fluffs,

We don't mind spinning around.

We are ballerina snowflakes

We dance day and night.

We whitewashed the trees

The roofs were covered with down,

The earth was covered with velvet

And they saved us from the cold. (1 min)

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Do you want to know how the story of Ice and Snowflake ended?

Suddenly a warm wind blew,

The sun sparkled in the sky,

All the snowdrifts have darkened -

Spring has come to our city.

What happened to our Ice?

Ice 7:

I was terribly upset

What Snowflake didn’t admit

The fact that I'm her sister...

Snowflake 8:

And under the sun's rays

Ice was crying with grief.

And, melting, she turned

Again in a drop of water.

Ice 9:

And Snowflake, between us,

Having won an argument with me,

Spring flowed in like a drop

In deep streams.

This is where the sisters met

Among a million drops.

Immediately recognizing each other

They laughed and hugged.

Snowflake 10:

And that we will be together

In summer it rains from the sky,

Ice 11:

And in winter spin in the sky

White snow, they swore. (3 min)