Download presentation on water in nature. Presentation "The role of water in nature". What is the difference between mineral water and regular water?

Synopsis "Water on Earth" (with introspection)

geography teacher MKOU secondary school No. 21

Lesson Objectives:

To consolidate knowledge about the atmosphere - to acquaint with the three states of water and its properties; - to develop a careful attitude to the water resources of our planet.

Equipment: - a globe, - a physical map of the hemispheres, - a poster with a rebus and the properties of water, - glasses of water and milk for experiments, salt, sugar, a spoon, - children's drawings about water in nature

Educational film "Hymn to Nature"

Presentation "Water in nature"

Lesson preparation:

It is written on the blackboard: number Each child has a notebook / printed / for checking homework.

During the classes

1. Checking homework.

Checking workplace equipment .

The attendants check the weather calendars.

a) conversation.

What topic did we study in the previous lessons? -Open the textbook on page 78-79 and work with questions on rubrics.

b) Individual work v workbook . The teacher reads each task, and the children fill out a workbook.

At the end of work, physical education.

2. Setting the goal of the lesson.

It is difficult for us to do without many minerals. But there is one wealth, without which it is generally impossible to do without. What kind of wealth, we learn from the riddle.

“What can’t be rolled up the mountain, Can’t be carried away in a sieve, And can’t be held in your hands?” (Water).
Why not roll out into the “mountain”? (flowing from top to bottom)
Why in the “sieve not to carry away”? (Through the holes will flow out)
And why can't you hold it in your hands? (Will pour out)

Today at the lesson we will talk about water. The topic of our lesson is “Water on Earth”. (The teacher writes the topic on the board, and the children in notebooks).

3. Explanation of new material.

a). The role of water in human life, plants and animals.

Guys, what role does water play in human life? Why and why is it necessary? How does a person use water? (Washes, drinks, cooks, washes dishes, floors, washes, bathes, in heating systems etc.).

Human blood is 98% water, human muscles are 70% water, and in general the human body, brain, body tissues are more than half water. The lack of water for a person is more dangerous than starvation: a person can live without food for more than one month, and without water - only a few days. A person consumes from 3 to 6 liters of water per day (depending on the climate).

Water is essential for both animals and plants. All plants "drink" water and receive the necessary substances for growth and development. Water is contained in the root, leaves, trunk, bark of a tree.

For example, to grow 1 kg of potatoes, you need 300 liters of water.

Without water, plants wither and may die. Animals also need water to live.

What conclusion can we draw?

Conclusion: All plants, animals, people need water for nutrition and cooling. There will be no life without water.

b) Water forms the water shell of our planet - the hydrosphere (from Greek words"gyra" - water, "sphere" - a ball.

Before you is a globe - a model of the Earth. It has the same symbols as on the map. Remember what blue and cyan mean? (Water). Green and brown? (Plains and mountains).

On the globe, these are continents or land. I spin the globe around its axis. What color is dominant? (blue). What follows from this?

On Earth, most of the water spaces are occupied by the oceans: Pacific, Atlantic, Indian and Arctic. (The teacher shows the oceans on the map, children -on the map in the textbook pp. 82-83).

Draw a diagram on the board:

Three quarters of the globe is occupied by water.

4. "Water in nature" presentation presentation.

Guys. Have you now seen where in nature you can find water? (Rivers, lakes, seas, springs, wells, puddles, dew, rain, fog, clouds, ice, snow, hail, frost)

5. Three states of water.

You said that cloud (fog), dew, snow are water. But somehow it is different in dew, snow, fog. What is unlike? (Cloud, fog is steam (water in the form of steam), dew is water in liquid form, snow is water in solid form, crystals).

What substance is water: liquid, solid or vapor?

Conclusion. Water is a special mineral, because it can simultaneously be in three states.

A diagram is drawn on the board and in notebooks.

Give examples where at home you can see water in the form of a liquid (from a tap), in the form of steam (we cook food - steam), in solid form (in the refrigerator)?

I wonder if water can go from liquid to vapor? (Yes).

Under what conditions will it happen faster? (It needs to be warmed up).

And from liquid to solid? (Cool down).

How about from solid to liquid? (It must be heated, because ice and snow melt in heat).

And from a solid state to go into vapor? (Yes)

Give examples. (In winter, mom dries clothes on the balcony. It freezes immediately, i.e. liquid water becomes ice, but still it dries up (almost), therefore, solid water can turn into steam.)

Can vapor become a liquid again or become a solid? (Yes, if you cool. Clouds, drops in the bathroom on the ceiling, hail).

Conclusion: Water is a wonderful mineral. It can be in three states at once and move from one to two others. There is no other such mineral resource!

Water properties.

Consider the properties of water and determine what properties it has.

On the board is a poster “Properties of water”. The listed properties are discovered gradually as they are determined as a result of experiments.

What is the encrypted word? How did you guess?

We will conduct experiments and unravel what properties of water are hidden on the poster.

Experience number 1. What happens to water if I drop it on the glass? (spread out)

Water doesn't hold its shape. Pour the water from the jar into a glass. What form has the water taken? (The shape of the glass).

Conclusion: Water has no form and takes the form of the vessel into which it is poured.

What property of water allowed us to pour it from a jar into a glass? (fluidity).

Experience number 2. Two glasses - with milk, with water, a spoon. What can you say about the color of milk? (White) What about water? (colorless) Immerse the spoon in a glass of water. We see the spoon from all sides.

Conclusion: Therefore, the water is transparent.

Experience number 3. I take sugar and salt. Which one is a mineral? (Salt) Why not sugar? (Manufactured by people). I put sugar and salt on a spoon into glasses with water, mix. What happened to salt and sugar? (melted) Why? (Water dissolved them)

Conclusion: Water is a universal solvent. It completely dissolved salt and sugar and remained transparent. For example, one liter of ocean water contains an average of 35 grams of salt (most of all table salt), which gives it a salty taste and makes it unsuitable for drinking and use in industry and agriculture.

Experience number 4. If we smell plain water, what does it smell like? And the taste?

Conclusion: The water is odorless and tasteless.

Which water tastes better rain, tap or spring? Why? You said that water has no taste.

Rain water does not have the salts that the body needs, so it seems tasteless. Tap water is poorly purified, filters are needed - means for purifying water. spring- dissolves minerals underground, passes through sand (natural filter), but it is better to boil before use.

What is the difference mineral water from the usual?

Fairy tales often talk about living and dead water. Most likely these fairy tales were born from life. Is there really water that has life-giving, healing power?

Student's story about mineral water (advance task). Regional component.

The distribution of water on Earth (drawing in the textbook p. 80)

6. Respect for water.

There is a lot of water on Earth, but clean water is becoming less and less. This is not because water supplies are depleted. And why? The threat of pollution loomed over the water. Who pollutes it?

Plants, factories, hydroelectric power plants consume a large number of water and at the same time pollute it with various waste products. With waste (used) waters of enterprises, various toxic substances enter rivers and lakes. Life, fish, plants, animals perish in the water. Decaying waters poison the air and become a source of serious diseases. The river is “sick”, its waters cannot be used by man.

Water must be saved! Taking care of the purity of the waters, we take care of our health, the beauty of the surrounding nature. Our country has adopted a number of laws aimed at protecting water. Their implementation is monitored by state authorities and environmentalists.

And how can you guys take care of the cleanliness of the reservoirs? (Do not throw cans, bottles, other garbage. Use water sparingly).

You can show posters, drawings calling for saving water.

“Close the faucet tightly so that the ocean does not flow out.” “Pour water sparingly, know how to cherish water.”

7. Students read poetry and show their drawings.

We study the hydrosphere

We answer questions.

Water is a mineral, water is ash - two - oh,

Water is the most important thing in the Universe.

Let me ask you then

What state is the water in?

/ Students' answers - in solid, liquid and gaseous. /

Asked the other day baby neighbor

At a trickle pouring from a tap:

Where are you from?

Water in response:

From afar;

From the ocean!

Then the kid walked in the forest

The whole glade sparkled with dew

Where are you from?

Asked for dew.

Believe and - I

From the ocean!

Gray fog fell on the field

The kid asked the fog

Where are you from?

And I, and I am a friend from the ocean!

Amazing isn't it?

In soup, tea, in every drop,

In the sound of ice

And in the rain

And in the dew and in the river

We will always respond

Ocean water!

8. Work on the textbook(p.80-81, p.84-85)

9. Summing up the lesson - presentation "Water in nature".

local history material

Cold, hot, fresh and mineral underground waters are common in our region. 12 types of Mineral water of our region are known all over the world.

The waters of Pyatigorye are unique natural underground drug factories.

In the cracks of failed volcanoes, waters saturated with hot solutions and gases accumulate, coming from deep pockets of solidified magma, and then rush to the earth's surface, forming dozens of springs at the foot of the mountains.

Our area has underground interstratal waters:

thermal, fresh, salty and mineral.

Thermal waters have a temperature of 90 degrees, with a very high salt content, these waters are still little used.

Mineral waters have not been fully studied and not taken into account, but the local population has been using them for a long time. In the area of the village of Podgornaya there is a source that treats skin diseases,

In the village of Nezlobnaya and in the area of the Georgievsky flour mill there are sources that heal gastrointestinal tract. In the region of Mount Lysoy - diseases of the musculoskeletal system. A hydropathic facility operating on iodine-bromine waters was built in the area of the city lake

The role of water in nature

WATER Water is the most abundant and important substance on earth. The total water reserves on the planet are 133,800 cubic kilometers. Of this amount, 96.5% is accounted for by the oceans, 17% is groundwater, 1.74% is glaciers and permanent snow. However, the total fresh water supply is only 2.53% of the total water supply.

Fresh water reserves on the planet are limited, but they are constantly updated. The rate of water renewal determines the water resources available to man. In the patriarchal era on Earth, the water cycle, which included plums, rains, snowfalls, floods, and so on, was, despite the cataclysms of nature, beneficial to humans. Rains, melt waters irrigated the earth, brought substances useful for plants, enlivened the very environment of nature.

With the development of civilization, when chemical fertilizers appeared, detergents, internal combustion engines, when human activity became nature-transforming, when a person separated himself from nature and stood above it, human waste began to pollute everything, and primarily reservoirs. In ancient times, when man lived in harmony with nature, any fresh water except for the swamp water, it was drinkable. There was sea water and just water, without any further definitions. It was believed that water is a mineral that a person should consume naturally.

Now a person is talking about a separate type of water - drinking water. In addition, there are waters of rivers, lakes, where a person can and cannot swim. There is wastewater, there are acid rains, there are emissions from the reservoir of waste from enterprises, from which all life in the water dies. Today, the water cycle in nature is closely connected with the man-made environment.

In the primary water shell of the globe, there was much less water than now (no more than 10% of the total amount of water in reservoirs and rivers at present). An additional amount of water appeared later as a result of the release of water, which is part of the earth's interior. According to experts, the Earth's mantle contains 10-12 times more water than the World Ocean. With an average depth of 4 km, the World Ocean covers about 71% of the planet's surface and contains 97.6% of the world's known free water reserves. Rivers and lakes contain 0.3% of the world's free water.

Glaciers are also large storages of moisture; up to 2.1% of the world's water reserves are concentrated in them. If all the glaciers melted, then the water level on Earth would rise by 64 m and about 1/8 of the land surface would be flooded with water. During the epoch of glaciation in Europe, Canada and Siberia, the thickness of the ice cover in mountainous areas reached 2 km. Currently, due to the warming of the Earth's climate, the boundaries of glaciers are gradually receding. This causes a slow rise in the level of water in the oceans.

Very great importance in the life of nature has the fact that the highest density of water is observed at a temperature of 4 ° C. When fresh water bodies cool in winter, as the temperature of the surface layers decreases, denser masses of water sink down, and warmer and less dense ones rise in their place from below. This happens until the water in the deep layers reaches a temperature of 4°C. At the same time, convection stops, since heavier water will be at the bottom. Further cooling of water occurs only from the surface, which explains the formation of ice in the surface layer of reservoirs. Thanks to this, life does not stop under the ice.

Sea water freezes at -1.91°C. With a further decrease in temperature to - 8.2 ° C, the precipitation of sodium sulfate begins, and only at a temperature of - 23 ° C sodium chloride precipitates from the solution. Since part of the brine leaves the ice during crystallization, its salinity is less than that of sea water. Perennial sea ice is so desalinated that drinking water can be obtained from it. The temperature of the maximum density of sea water is below the freezing point. This is the reason for rather intense convection, covering a significant thickness of sea water and making it difficult to freeze. The heat capacity of sea water is in third place after the heat capacity of hydrogen and liquid ammonia.

Snowflakes, as a rule, come in the form of six- and twelve-ray stars, hexagonal plates, and hexagonal prisms. With a decrease in air temperature, the size of the formed crystals decreases and the variety of their forms increases. Features of crystal growth in air are associated with the presence of water vapor in it.

Today, all people know the fact that water is the source of life on Earth.