Abstract of the lesson of the circle “Snow, ice and their properties. Why is snow white even though an individual snowflake is transparent? Why is snow white and water clear?

Snow makes winter white, it seems to hide the darkness and dirt of autumn, which is why it brings so much joy. Children especially love it. For them, snow is one of the main winter funs. Children make fortresses and snowmen out of it, ski and sled on it, or just wallow in it for hours without a visible goal. It is no wonder that there comes a time when the kids begin to ask their parents why the snow is white.

The nature of light and its role

To answer this question exhaustively and in an accessible way, adults must have some knowledge about light, color perception and snow. But you need to start with visible light. Everything around is permeated with electromagnetic waves, but people are able to see only a tiny fraction of them. The visible part of the spectrum consists of wavelengths from 550 to 630 nanometers.

Anything outside this narrow spectrum remains invisible to the human eye. True, the waves can be felt by other senses, for example, ultraviolet cannot be seen, but it warms the skin and can even burn it if you stay on a sunny beach for a long time.

Vision is a priceless gift of nature, thanks to which people have the opportunity to create a stable picture of being and to know the world. However, without light, human vision becomes a useless tool. This is easy to show to a child by entering a room where there are no windows, such as a bathroom. While the light is on, objects around are visible, their colors are distinguishable. But as soon as the light bulb goes out, the room plunges into impenetrable darkness, all things and colors cease to exist for vision, until they are again illuminated by the sun, a living fire or an electric light bulb.

Natural phenomena are of great interest to children. All mothers are faced with simple questions of little whys and whys: “Why is the snow white and the ice transparent?” According to the logic of things, snow is a set of compressed snowflakes consisting of water. Water, in itself, is transparent, which means that snow should also be invisible. But everything looks different. When pronouncing the word snow, the concept of snow-white immediately pops up. Let's consider from the point of view of physics why snow white color.

Physical riddle

A snowflake is made up of microscopic water crystals. Do we just think that the snowdrift is white. After all, the rainbow is also multi-colored, and this is just an optical illusion. Snow looks white to us when the sun shines on it. Depending on the brightness of the light wave, the color of the snow can be:

• blue;
• grey;
• blue;
• Pink.

For example, when it is cloudy outside, the snow appears gray or blue, and at sunset it appears pink.

It is true that snow is white precisely because of the properties of water. transparent - white snow. A snowdrift of snow is billions of snowflakes, each of which is a crystalline compound of water. The main physical property of water is the ability to absorb red and infrared spectral rays. When the rays pass through the crystals, the light from the sun does not pass through warm colors spectrum, and cold - passes. That is why the color of the snow becomes from blue to gray.

If there is no loss of spectral colors, then the color of the snow appears white.

But what about ice?

Ice is also water, only in a different state of aggregation. Then it is transparent and not white? Ice is a crystalline compound. A crystal is always transparent and it doesn't matter if it's ice or crystalline salt. An ice block is also a kind of crystal, only big size. Let's do a microscopic examination of the ice.

A snowflake under a microscope in the light is transparent. This is due to the purity and absence of impurities and air bubbles. Letting the sun's rays through, ice, like a snowflake, will also be transparent.

But the snowdrift is a lot of crystalline snowflakes that reflect the sun's rays. If the surface of the snowflakes were perfectly flat, then the snow would be transparent. But since snowflakes fall randomly into a snowdrift, the light is refracted at different angles. This gives the snowdrift a white color. No wonder they say that snow, as if blinding with whiteness. The reflection of sunlight makes us squint against the bright white snow.

If we compare a huge ice floe and a snowdrift, then the rays pass through the ice without hindrance, and they are refracted from the snow. If grind ice block, it will turn white, since the water crystals will not be compressed into one.

Rays will be refracted and reflected. This is what explains physical phenomenon snow is white and ice is clear. By the way, there are cases of color precipitation. Due to chemical impurities, the snow acquires a shade that is not familiar to our eyes.

Children always look forward to winter. Making a snowman, sledding and jumping into snowdrifts is interesting and enjoyable! After active games fresh air, they often find inspiration, and questions begin: “Why is the sun yellow and snow white”? Few people explain the reasons for these phenomena to the little “why”s. Let's answer at least one of the above questions. So why is snow white?

A short excursion into physics

The earth is surrounded electromagnetic waves. They are everywhere, but mostly invisible to living beings. What the eye perceives is considered a color - electromagnetic radiation, a wave that gives color sensation. The main source of electromagnetic waves is the Sun. Its rays include all primary colors:

• red;
• yellow;
• blue;
• blue;
• green;
• orange;
• violet.

If all the colors merge together, a white tint is formed, and the sun's rays are just white.

Related materials:

Why don't they drain the water in the batteries in summer?

Every object on earth transmits (reflects, absorbs) sunlight. There are those who fully display it, such as ice. Each individual snowflake is the same ice.

Interesting Snow Facts:

• Half of the inhabitants the globe I have never seen real snow, only in pictures.
• In 1949, in the Sahara for the first and last time snow. The snowfall continued for more than half an hour.

snow and color

Snowflakes fall on the ground randomly, and as a result, the snowball does not transmit fully electromagnetic waves (sunlight). Therefore, if you make a dent in a snowdrift in sunny weather, the snow appears green-yellow. When overcast, it looks blue. If there is a bright red sunset in the sky - pink. The surface of the snowdrift displays all the colors of the rainbow when it is clear and sunny outside.

In latitudes that are closer to the Earth's poles, the snow appears to be a rich red color. Scientists often note a similar phenomenon in the Arctic. In the United States, namely the state of California, in 1955, residents observed a green snowfall. In 1969, a black snowfall hit Switzerland. In Russia, yellow snow fell in 2015, which was written about for a long time in the media. air masses brought with them African sand dust, which painted precipitation in an unusual color for them.

Olga Chertova
Summary of the lesson of the circle "Snow, ice and their properties"

On circle lessons"Young ecologist" we are with children senior group we continue to experiment. This time, we are experimenting properties of snow and ice.

TARGET: Form an idea of snow, ice and their properties.

Introduce children to physical properties of snow and ice.

TASKS:

Educational. Help children understand why when the temperature changes snow and ice change their properties.

Consolidate knowledge about properties of snow and ice.

Teach children to analyze, draw conclusions in the process of experimentation.

Developing. Develop thinking, the ability to express one's thoughts consistently, interest in winter events nature.

Educational. Cause joy from discoveries obtained as a result of experiments.

preliminary work: Monitoring snow, viewing snowflakes, characteristics snow: dry (wet, loose (dense, cold, deep, sparkling, crumbly, playing with snow, experiments, reading the story “The First snow” E. Trutneva.

Materials and equipment: disposable plates for snow(on each table there is a deep and flat plate, snow, magnifiers by the number of children, half a cut apple on a napkin, a disposable spoon, three containers of water, circles different color , visual models of snowflakes and ice floes with the designation properties of snow and ice, napkins and towel.

Guys, what season is it talking about in this enigma:

Snow on the fields,

Ice on the rivers

Blizzard walks -

When does it happen? (in winter)

And the following riddles talk about phenomena inanimate nature winters. Guess them.

He is fluffy, silver,

But don't touch him with your hand

Become a little clean

How to catch in the palm of your hand. (snow)

Transparent as glass

Don't put it in the window. (Ice)

An asterisk circled

A little in the air

Sat and melted

On my palm. (Snowflake)

The teacher draws the attention of children to artificial snowflakes. Are they real? When and where can you see real snowflakes?

Listen to how interesting the writer talks about snowflakes

V. Arkhangelsky. (Children are read about how snowflakes are formed).

What happens snow? Turns out, snow is different. On very frosty days, it is crispy and crumbles. But if it gets a little warmer outside and a light, slight frost sets in, then snow becomes sticky, and then we will be able to fashion a snowman, build a snow fortress, and play snowballs.

And when does it happen snow and ice(Answers).

Once snow and ice is only in winter, then they are probably somewhat similar to each other. How do you think? (Answers). Today we will conduct experiments and find out how they are similar to each other snow and ice and how they differ.

Experience is practical actions with objects to recognize them properties.

I got it yesterday snow and ice and put it on plates, but I wonder what happened to him? I suggest heading to the snow lab, but it's not easy to enter. (passing through the arc, the children answer the question "Where does the snowflake live?")

Now we are research scientists, we will find out what they are snow and ice and what are their properties. And our assistant will be a special device for research. Find it on your tables, what is this device called? (magnifier). What is a magnifying glass? (magnifying glass).

Guys, what happened to snow? (melted) Why?

Means, snow and ice are formed from water under the influence of frost and melt in heat.

(a snowflake with the image 1 is attached to the board properties, a droplet is drawn on the snowflake water: the snow melts in the heat).

Let's take a closer look at the melted snow. What do you see? (dirty water). Guys, I saw some children eat snow. Are they doing the right thing? Which one then snow to the touch? (cold). Is it possible to eat snow? (No, snow cold and can be dirty).

Experience number 1. "Defining Color".

Let's compare: what color is the water, snow and ice(snow white, water and ice are colorless) What else is white? (attached 2 snowflake: snow white - cotton wool in the center of the snowflake, colorless ice).

What colour snow? (white)

What color is ice? (colorless)

Experience number 2. "The Definition of Transparency".

Let's do an experiment. Under your plates lie geometric figures, name them (circles). What color are they? Put one circle on an empty plate, on top we put snow, lower the other into the water, put the third circle under the ice. Where is the circle visible and where not? Why? (on the board is attached 3 snowflake: snow opaque - drawn closed eye, transparent ice - open eye).

Experience number 3. "Smell Definition".

Guys, how do you know snow and ice smell? (need to sniff). Let's smell the apple first, which apple? (fragrant, fragrant). And now snow(at no smell of snow) (attached 4 snowflake: snow and ice have no smell - a nose is drawn on a snowflake).

Let's try to stick in snow stick what happened? Can you stick a stick in ice? It can be concluded that loose snow and ice is solid.

Take a handful snow and pour it out. How can you call it property of snow? (loose). What about ice? I "accidentally" dropped the ice, what happened to it? (it's cracked, it's fragile).

Fizkulminutka:

Snow fluffy everything flies, (raise hands up and slowly lower)

And the blizzard keeps howling.

How many snow covered, (show snowdrifts)

All paths are covered!

We'll clear the paths (imitate actions)

And let's play snowballs. (walking)

The snow is white today, white, (raise hands up and down)

It is light all around.

We put on gloves (put on gloves)

and we'll wear gloves (wear each finger)

We will wear each finger,

Will you fur coats keep us warm.

Well done! You showed me so many experiments, and now I want to show you, sit down more comfortably. See A: I have three jars. Pour water into one (the child is invited to check the temperature of the water, (cold). In the second we pour warm, but how do we get warm water what water to pour at first: hot or cold, why? (cold then hot). In the third jar I will pour hot. In three jars I will lower snow at the same time. Where the snow melted faster, but where is slower? (the warmer the water, the faster it melted snow, melting speed snow depends on water temperature).

Guys, now let's remember what properties of snow and ice? (at the end of each experiment, snowflakes with properties of snow and ice). Children's attention is drawn to snow and ice is frozen water.

Let's now put together everything we've learned about snow and ice.

Snow is white, opaque, loose, free-flowing, under the influence of heat turns into water.

And ice - colorless, transparent, hard, brittle, turns into water under the influence of heat.

And now that we have met properties of snow, let's try to cut out the snowflakes ourselves and see what we get. (Children cut out snowflakes).

Summarizing classes: How much did we learn today about snow, it's time to go back. Did you like our class? What do you remember the most?

Our Ksyusha became a little bitch. And mom and dad became walking mini-encyclopedias. Therefore, we decided to help parents of the same why children create a new section “” and publish answers to the most common children's questions in it. We will try to adapt all the answers as much as possible for preschool children, so that it is easier for parents to explain the complex laws of nature to them.

It's winter now and that's why, of course, questions about why are in the TOP of why girls :) That's why we publish our answers to the snowiest questions.

What is snow?

Snowflakes are formed in the same way as raindrops: water evaporates from the seas and oceans and rises to the sky, where it cools down and collects into droplets. When it is very cold, water droplets freeze into ice crystals. They fall to the ground in the form of snow. The melted snow evaporates or flows into streams, from where it begins its journey to heaven again.

Why is snow white?

If snowflakes and droplets are of the same nature, then why are droplets transparent and snowflakes white? The fact is that each individual snowflake is transparent in itself, but together they fall to the ground in a chaotic manner and form a loose mass. Snowflakes lie to each other at different angles. Sunlight is reflected first in one snowflake, then in another, and so on, until it is directed back. It turns out that the snow completely reflects the sunlight, and since the rays of the sun are white, the snow is also white. If the rays of our Sun were yellow and red, then the snow would also be yellow or red. At sunset or sunrise, when we see the pink rays of the sun, the snow also turns pink.

Why do snow and ice melt from salt?

Snow and ice are water that freezes (becomes solid) at 0 degrees Celsius. If you add salt to water, you get a saline solution that freezes at temperatures below 0. If you sprinkle salt on ice or snow, we will make them melt, since salt dissolves in water and lowers its freezing point.

First, the ice around the salt crystal will melt, and then the melting process will spread further from this point.

Which snow melts faster?

Dirty snow melts faster because:

1. There are also salts in the mud, which speed up the process of snow melting.
2. The mud is usually dark, which means that it absorbs the sun's rays and as a result heats up quickly, warming the snow with it.

Can you eat snow?

Snow tends to collect dust on itself. City dust, in addition to the usual natural dirt and bacteria, contains a lot of heavy metals and other toxic substances that are very dangerous for humans. By eating snow, a person absorbs all these toxic substances and exposes his life to the danger of poisoning.

High in the mountains, pure snow falls without dangerous impurities, but such water is also not good for the body, since it lacks the most important salts that are usually found in drinking water. There is only one conclusion: eating snow is not only unhealthy, but also dangerous to health.

Are there identical snowflakes in the world?

More than a hundred years ago, when the first cameras first appeared, one man, nicknamed “Snezhika”, decided to photograph snowflakes under a microscope. He took 5,000 shots, but not a single pattern of snowflakes was repeated. Many years have passed, and scientists are still arguing: are there identical snowflakes. They even created 2 twin snowflakes in their lab, but that still didn't end their argument. Starting another study, scientists came to the conclusion that snowflakes can differ not only in the external pattern, but also internal structure. This means that even if the snowflakes are the same externally, then most likely their internal structure is still different.