State Board | 6th Class Science | 6th Class Science – Natural Resources |

natural resources natural resources are the resources that are naturally available in the nature water and a are the most important natural resources water water constitutes 70% of our Earth's surface it is in the form of C River Lake Pend and also as moisture in the atmosphere nature of water water is available to us in three different forms namely solid liquid and gas pure water is colorless tasteless and odorless water changes into vapor becomes dense and reaches the earth as rain importance of water water is the main factor responsible for life on earth water is useful for metabolic activities in living organisms agriculture irrigation constructions transport washing clots hydro electricity extinguishing the fire etc different states of water water exist in three different states it exists as ice in solid state water in liquid state and as vapor in gaseous state evaporation and condensation water sources like lakes ponds and wells are present in many places in summer the level of these sources get reduced and some of them get totally dried up in the same way the water in seas lakes and rivers continuously enter air this is called moisture in a odd humidity this process in which water changes into vapour is called evaporation do other liquids also evaporate like water collect six small equal sized Injection bottles with lid six saucers like plates and a funnel with the help of funnel fill the first bottle with petrol second bottle with alcohol third bottle with kerosene fourth bottle with water fifth bottle with ground nut oil and six the bottle with palm oil pour the liquids in separate plates keep the blades at one place for half an hour now pour the liquids into the bottles again check the level of liquid in each bottle in which bottle is the level of liquid high and in which it is low note down in the notebook a rate of evaporation differs from liquid to liquid rate of evaporation differs with place and time water evaporates into air rises up and form clouds when cold air comes in contact with the clouds these clouds change into water drops this process is called condensation water cycle water on the earth rises up in the form of water vapour is cooled and written earth in the form of rain this is called as water cycle continuous exchange of water between land sea and atmosphere is known as water cycle floods floods occur due to heavy rainfall the overflow of river streams canals drainage canals is due to these floods due to this fields are submerged crops are damaged causing loss houses collapse huts are washed away along with the articles in the households there is fear of animals and human beings also being washed away normal life gets disrupted famines occur if rains don't fall in due time in required amount living organisms does not obtain water air becomes dry soil dries up and forms cracks due to lack of water reverse ponds eggs dry draught conditions mean crops do not grow due to lack of water this results in depth of food animals died due to lack of water and food in severe conditions of drought and famine people may fight among themselves for food and water in cities serious canals are not in order or regularize so roads are becoming water clogged even for scanty rains water pollution the presence of harmful substances in water is called water pollution and that water is called polluted water water gets polluted in two ways one natural – artificial artificial pollution of water industrial wastes as the industries require water they are located nearer to the like sources of water lakes rivers and ponds industrially discharged wastes contain poisonous chemicals radioactive substances which are sent into water sources cause water pollution this is not only fatal to Mara in life but even human beings are prone to diseases by drinking this water agricultural waste the excessive use of manuals fungicides and pesticides in crops cause pollution of groundwater lakes ponds rivers and seas due to crude oil throughout the world special ships carrying crude oil tankers travel from one country to another by sea routes if there is an accident this oil is released into the seawater and spreads as a layer for many kilometers on the sea water due to Salter houses water is being looted due to waste from salsa houses poultry forms dairy forms which are released into the water thus polluting it atomic reactors wastes discharged from these atomic reactors should be buried underground are thrown into the sea water shortage almost 42 percent of land has lost it fertility thus turning it into a wasteland the groundwater in 5:48 mandals out of 1104 bundles in our state has reduced below 10 meters these areas are prone to serve shortage of water man is responsible for the reason of drought conditions and water shortage is mainly due to insufficient plant growth drought situations are due to irregular distribution of water reckless deforestation unscientific grazing of crops air the eighth color of the earth extends up to 700 kilometers from its surface this air cover is known as atmosphere atmosphere contain carbon dioxide hydrogen inert gases dust particles etc components of here air is not a single substance it consists of nitrogen oxygen carbon dioxide water vapor along with inert gases like helium neon etc it also consists of dust particles and smoke therefore air is called a mixture to demonstrate carbon dioxide is present in the air take a glass of water add some lime to it and still well leave it aside for about two hours afterwards transfer the settled water on the surface into a saucer keep this aside for about half an hour and then observe a white layer is formed on the lime water the reason for this is carbon dioxide this demonstrate that it contains carbon dioxide air contains car dioxide to demonstrate that a contains water rapper take an ice cream from an ice-cream vendor break it into pieces and fill them in a dry glass place this glass on the table absorb the surface of the glass after some time the water vapor into a turn into droplets of water when it comes into contact with the coolness of ice-cream this proves the presence of water vapor in the air air contains water vapor air has wait collect a broomstick a thread and Alpen two balloons of equal size tie two balloons blown with air with equal volume the broomstick must be horizontal make a tiny hole to one balloon with the help of a pin on one side the air goes out and the broomstick with the punctured balloon goes up showing that the balloon which has air in it has more weight ale has weight 8 exerts upward pressure fill the glass tumbler completely with water up to the brim place the paper over it and invert the glass with paper it is because the air from below is exerting pressure and this pressure is supporting the paper this is called upward pressure of air air has downward pressure you know what happens when bottles and tins filled with water get punctured the leakage of water from the holes show that a exerts pressure on the surface of water it is a that releases water out from a siphon pump air has downward pressure air exits sideward pressure collect a plastic mineral water bottle along with its cap and some hot water about 50 degrees Celsius to 60 degree Celsius pour hot water in the bottle close it and shake it on all sides open it throw away the water recap it place it on a table and observe the sides of the bottle are pulled inwards this demonstrates that air has sideward pressure air has sideward pressure measuring atmospheric pressure it has weight any substance that has weight exerts pressure air exits pressure on Earth's surface this pressure is called atmospheric pressure barometer is used to measure the atmospheric pressure there are many kinds of barometers in usage cistern barometer is one among them construction of barometer collect a thick-walled glass tube of one meter long five centimeter diameter closed at one end 250 ml trough two cages mercury a paid of Glos as shown in the diagram wear a pair of gloves two two hands and fill the trough with some mercury pour pure mercury in the glass tube close the open end of the tube with your thumb and move the tube up and down Sudar the air bubbles will be removed place the tube in a trough containing mercury and remove your thumb a portion of mercury in the tube falls down into the trough mercury in the tube stands still at a certain height of centimeters this is called mercury column vacuum is formed above the surface of mercury column this is called Torricelli vacuum the height of mercury column near the sea level will be 76 centimeters this is called normal atmospheric pressure working of a barometer the pressure accepted by the atmosphere on the surface of the mercury in the trough is equal to the pressure accepted at the same level in the tube that's why the height of 76 centimeters of mercury column is equal to the atmospheric pressure because of this the height of mercury is used in measuring the atmospheric pressure this barometer is not convenient to carry from place to place anyroad barometer this is a possible barometer because it does not use any liquid this is used to measure the atmospheric pressure in inflated tires of vehicles atmospheric pressure is measured in Millburn enoyed barometer is used to measure the air pressure in inflated vehicle tires air pollution causes and control pollution is mainly of four types one air pollution two water pollution three land pollution four noise pollution now let us learn about air pollution the presence of harmful substances in the air is called air pollution Indian government has set up the central Pollution Control Board at national level and the state government has set up the Andhra Pradesh Pollution Control Board presently compressed natural gas CNG is being used by using this we need not worry about the factors causing pollution except carbon dioxide factors affecting pollution one carbon monoxide carbon monoxide is evolved if the fuel is not used completely if there is sufficient supply of oxygen carbon dioxide is evolved instead of carbon monoxide carbon monoxide is harmful than carbon dioxide this is emitted from electricity generating projects which depend on coal and when fuel in vehicles does not burn completely sulfur dioxides fossil fuels contain sulfur on commission they form sulfur dioxide causing acid rains sulfur dioxide and sulfur trioxide are released when volcanoes erupt when fuels like petroleum diesel and kerosene burned when ores containing sulfur are burnt in metallurgy nitrogen oxides nitrogen oxides like nitrogen dioxide nitrogen trioxide nitric oxide also lead to acid rains nitrogen oxides evolved due to intense temperature in the environment acid rains increase the acidity of soil plants are destroyed aquatic beings lose the lives and water pollution increases dust smoke the suspended particles in air like microscopic dust particles are emitted from vehicles and industries these are called SPM suspended particulate matter reasons for pollution vehicles vehicles which run on diesel and petrol emit gases which contains pollutants like sulfur thermal power plants coal is used as fuel in these plants coal contains sulfur substances emission of sulfur dioxide carbon monoxide and carbon dioxide take place on combustion of coal industries many industries release chemical substances the sulfur and nitrogen oxides released by industries are the cause for acid rains the beauty of the historic Taj Mahal is also mad by the oxides of sulfur and nitrogen released air pollution is responsible for deadly diseases like asthma TB and cancer measures to control pollution the vehicles should be constructed in such a way that the fuel used in it is completely combusted we can prevent pollution using compressed natural gas using petrol without lead refinement of polluted air released from factories using hydroelectric stations solar energy wind energy hydrogen as fuel instead of thermal power plants the quantity of oxygen in air is reduced due to deforestation deforestation should be stopped and effort station should be promoted greenhouse effect global warming earth absorbs some part of the radiation from sun and emits some part of it onto the atmosphere gases like carbon dioxide methane ozone water vapor which are known as greenhouse gases absorb the heat reflected by the year as a result atmosphere gets heated up as there is enormous release of gases like carbon dioxide into the atmosphere earth is absorbing more heat of Sun and it is getting heated this is known as greenhouse effect or global warming


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