Ch 1 Natural Resourses.pptx

Std 6 Chapter 1 Natural Resources- Air, Water and Land
Science Maharashtra Board

1. STD 6 - SCIENCE LESSON- 1 NATURAL RESOURCES Air, Land and Water Preeti Kshatriya

2. Answer…….. 1. If there are four sheep, two dogs and one herds-men, how many feet are there? Answer: Two. Sheep have hooves; dogs have paws; only people have feet. 2. The leaves are on the fruit, The fruits is on the leaves. Answer: A pineapple. 3. What color is the wind? Answer: Blew. If fish lived on land, where would they live? Answer: In Finland.

3. OBSERVE AND ANSWER Ans 1. In the Sky . Ans 2. Grass ( on Land) Ans 4. River comes from the mountains Ans 5. In the sky Ans 6. In the water Ans 7. Water.

4. NATURAL RESOURCES….. Air ,Water and Land are the factors important for sustaining the living world on earth and for fulfilling their basic needs. They are called Natural Resources . Sustain – to keep something alive.

5. The Spheres on the earth HYDROSPHERE(Water) LITHOSPHERE(Land) ATMOSPHERE( Air) There are Three Main Spheres on earth.

6. HYDROSPERE : Hydro: Water A hydrosphere is the total amount of water present on Earth. The hydrosphere includes water that is on the surface of the planet, underground, and in the air. A planet's hydrosphere can be liquid, vapor, or ice. On Earth, liquid water exists on the surface in the form of oceans, lakes and rivers.

7. LITHOSHERE_ Land The Lithosphere is the Earth's outermost layer, composed of rocks in the crust and the upper mantle The lithosphere includes the brittle upper portion of the mantle and the crust, the outermost layers of Earth’s structure.

8. ATMOSPHERE- Air The Atmosphere is the layer of air that surrounds the EARTH.

9. BIOSPHERE (Bio- Living) The living things and the parts of the Atmosphere, Hydrosphere and Lithosphere which they occupy are together called the Biosphere.

10. Proportion of Land and Water. The proportion of Land on the Earth is about … 29% The proportion of water on the Earth is around… 71% 71% + 29% = 100% Land 29% Water 71% 1.2: Proportion of Land and Water.

11. Page 2

12. 5 layers of the atmosphere

13. Details….. 1. Troposphere: Almost 70% of the mass of the atmosphere is contained in this layer. 2. Stratosphere: This region has the maximum concentration of Ozone. The gas absorbs ultraviolet radiation of the sun 3. Mesosphere: This layer has been so named because of its situation in the middle of the five layers that is divided according to the thermal conditions of the atmosphere 4. Thermosphere: Temperature rises with increasing altitude. 5. Exosphere: This is the outermost layer of the atmosphere, and also the transition zone between the earth’s atmosphere and interplanetary space. The air is very thin here.

14. AIR- its various constituents The air in the atmosphere contains Nitrogen, Oxygen , Carbon- dioxide , Six types of inert gases, Nitrogen dioxide , Sulphur dioxide , Water vapour and Dust particles.

15. Troposphere – 80% of gases in the air. Stratosphere – 19 % of the gases in the air. Mesosphere – Proportion of gases is less Ionosphere – Proportion of gases is still lesser. Exosphere – There are no gases found. The proportion of gases in different spheres of the earth is as follows

16. SOME USES OF GASES IN AIR

17. Uses of Carbon di oxide For food production in plant As a fire estinguisher Oxygen Nitrogen is used in Air tight packaging of foodstuff

18. Xenon used as flash lights

19. AIR POLLUTION The smoke released from the factories and chimneys gets mixed with the air, disturbing the balance between the constituents of air. This is called Air pollution. Air pollution is caused by vehicles, industries and other sources wherever there is incomplete combustion of fuels. Air pollution is increasing day by day. Harmful air pollutants: Nitrogen dioxide, sulphur dioxide, Carbon dioxide CO 2 , Carbon monoxide CO and Soot.

20. Ozone layer

21. Water Life is impossible without water. We should drink 3 to 4 litres of water a day, for our body to run smoothly. All organism require water.

22. WATER Water is the most important natural resource. Even though we have 71% of water on the planet , a very little amount is available for drinking. Thus we should use this natural resource very sparingly and carefully. 0.3 Ground water, ice Sea and ocean 97.00 Ground water and ice 2.70 Water available for 0.30 drinking ----------- 100.00 97% 2.7% 0.3%

23. WATER SHORTAGE Due to uncontrolled use of water for an increasing population , industry and farming….. There is shortage of water and this is a serious problem. Thus …we should always remember to water Sparingly.

24. Land What is land made up of? Ans. Land is made up of Soil, Rocks , Stone etc. What do you see on Land? Ans. Mountains, valleys, rivers, oceans can be seen on the land. Can you tell page 5

25. In urban region we can see buildings and other construction, bridges, roads etc.

26. In rural areas we can see farms and orchards and some tree cover

27. What has man created on Land? Ans. Man has created different types of Shelters, roads for transport and agricultural farms on the land . If a deep pit is dug in the ground, what do you find there? Ans. We see different layers of soil, if a deep pit is dug in the ground .

28. Is the land flat everywhere? Ans NO , Land is Uneven. At some places there are mountains and hills while at some places there are valleys. Does Man produces Soil/ Land? Ans. Man can artificially produce land by reclamation.

29. LAND

30. LAYERS OF LAND Layer of soil : The Sequence with which the layers of soil are present from top to bottom are as follows Humus Soil Immature Soil Layer of soil and small rocks Bedrock

31. Humus : The topmost layer of soil is formed by decomposition of the remains of the plants and animals . This is known as humus. It is usually found in dense forests. Immature Soil : The land below humus soil is full of sand, soil, small stones, worms, and insects. Soil and pieces of bedrock are found below this layer of land. This soil is immature. Bedrock : Below immature soil there is bedrock. The main minerals of the soil are found in the bedrock. The type of soil is different in different regions. This is dependent on the colour and texture of the constituents there in.

32. HUMUS

33. PROCESS OF SOIL FORMATION The soil on the land is formed by a natural process. The abiotic components of soil are supplied through the weathering of the bedrock. Due to the heat, cold and water of the sun, wind and rain respectively, the bedrock breaks down into pieces. Stones, sand and soil are formed from these pieces. Microbes, worms and insects are found among them. Rodents like mice and rats are also found here. The roots of trees growing on the land also help weathering of rocks. The process of soil formation is slow and continuous. It takes about a thousand years for a 2.5 cm thick layer of mature soil to form.

34. WHAT WE SHOULD REMEMBER

35. INSTITUTES AT WORK