Some important questions is science

1. Explain the basis and working of atomic reactor? V.V.important
1.      Basis of atomic reactor: - A controlled chain reactions is the basis of atomic reactor.
2.      Fuel: - The fuel used in an atomic reactor is Uranium-235
3.      Working: - The nuclear fission of U-235 is carried out by bombarding it with slow neutrons. The nuclear chain reaction is thus set in. it is controlled by boron steel or cadmium rods. Thus, the liberation of energy in the fission process is controlled.
4.      The energy released is used to heat water to convert it into steam, the steam in turn is used to turn turbines and generate electricity.

2. What is nitrogen fixation? Explain its physical process?  V.V.important
Ans:  1. Nitrogen fixation: - The Process by which atmospheric nitrogen is converted into its compound is called Nitrogen fixation.
          2. Physical Process of Nitrogen fixation: -
[A] During lightning, the atmospheric nitrogen is oxidized to nitrogen dioxide NO2
[b] The Nitrogen dioxide then gets dissolved in rain water to form nitrous and nitric acids which are taken to the soil along
      With the rain Water.
[c] In the soil, they react with other elements to form nitrogen compounds.
[d] This process of Nitrogen fixation is called Physical process of Nitrogen fixation

1. Give Four Physical Properties of Hydrogen Sulphide?
1. Hydrogen sulphide gas is colourless 2. It has rotten egg like odour 3. It is heavier than air 4. It is partially soluble in water.

2. Name the allotropes of phosphorous.
The allotropes are: -1. Yellow phosphorus    2.Red phosphorus

3. Fuel containing less proportion of sulphur should be used.
 1. Fossil fuel contains sulphur. Combustion of fossil fuels releases oxides of sulphur, i.e. mainly sulphur dioxide
 2. Sulphur dioxide is a pollutant. It causes irritation of eyes, throat. It may also lead to bronchitis and other respiratory

4. Ethylene undergoes addition reaction
1. Ethylene is an unsaturated hydrocarbon. 2. in its molecule there is a Carbon-Carbon double bond (C=C). Hence,

5. Cancer cannot be diagnosed (Cured) in its early stage.
 1. Cancer does not show any symptom for a long time.
 2. The detection or diagnosis of cancer, therefore, is not possible in its early stage.

6. Write Molecular formula for 1. Limonite (2Fe2O3) 2. Haematite (Fe2O3) 3. Copper glance (Cu2S)4. Cup rite (Cu2O)

7.Write two functions of Vitamin B12
     1. Vitamin B12 is essential for maturation of cells.
     2. Vitamin B12 is necessary for the proper functioning of the nervous System
     3. B12 plays an important role in the formation of red blood corpuscles.

8. Which are fat soluble vitamin ans: - 1.Vitamin A      2.Vitamin D         3.Vitamin E           4.Vitamin K

9. What is the importance of the following in our diet?
1. Vitamin K: - Vitamin K helps in the formation of prothrombin, a kind of protein necessary for the clotting of blood.
2. Minerals: - Minerals are necessary for regulatory and protective functions in the body.

10. Four methods of concentration of ores Ch 4
Ans: - The Four methods used for removing gangue from ores are
1. Washing 2. Froth floatation 3. Magnetic separation 4. Chemical Separation

11. Name Four Alloy of Steel?
Ans: - 1. Stainless Steel 2. Tungsten Steel 3. Manganese Steel 4. Chrome Steel.

12. What is Magnalium?

Ans: - Magnalium is an alloy of aluminium. It Contains aluminium and magnesium.

13. What is blister Copper?

Ans; - The Copper obtained from the converter, which has blistered appearance on the surface is called Blister Copper. Due to escaping of SO2 gas from the molten mass of the metal as it cools, the metal surface has blistered appearance. It contains 98.5% Copper.

14. Name the important minerals Containing Phosphorus?

Ans: - The Important minerals containing phosphorus are:-1. Phosphorite Ca3 {Po4}2      2. Fluorapatite 3Ca3 {PO4}2  
            3. Chlorapatite 3Ca3 {PO4}2    4. Wavellite 4ALPO4

15.  Name two secondary pollutants.
Ans: - Secondary pollutants 1. Ozone    2. Peroxyacetyl nitrate {PAN}

16. Write two tests to identify hydrogen sulphide gas.

Ans: - 1. Hydrogen sulphide gas has a smell of rotten eggs.
           2. A stripe of moist lead acetate paper turns black when it comes in contact with H2S

17. Name two endogenous processes by which vegetables and fruit perish
Ans: -   1.Respiration     2. Transpiration

18.  Enlist the names of any four natural food preservatives.                 

    Ans--      1. Sugar    2.Salt   3. Oil and 4.Spices.

19. Solar energy is essential for Bio-chemical cycle.

ANS: - The energy required for the operation of different biogeochemical cycles is obtained from solar energy.
Therefore, solar energy is essential for Bio-chemical cycle

20. State the effect of Kidney failure on health

1.  Oedema occurs due to the accumulation of poisonous substances in the tissue of the body.
     Increase in urea of blood leading to Uraemia.

21. Name the important alloy of copper and their Compositions (Important)

Ans: - 1. Brass: - Copper {60-90%}, Zinc {40-10%} 2. Bronze: - Copper {81-90%}, Tin {19-10%}
            3.German silver: - Copper: - {50%}, Zinc {25%}, Nickel {25%}    4. Bell Metal: - Copper: - {78%}, Tin {22%}         
            5.Gun Metal: - Copper: - {88%}, Tin {10%}, Zinc {2%}.

22. Producer V/S Consumer

23. A. Give the uses of Sulphur in the field of agriculture.

23. B. Write the four causes of human diseases.
 Ans: - 1. Organic failure 2. Metabolic disorders 3. Hereditary defects 4. Environmental pollutants.

23. C. State the effect of deficiency of iodine on health.
Ans: - Deficiency of iodine causes goitre, i.e. enlargement of the thyroid gland.

24. Give important application of each of the following. 1. Duralumin 2. Magnalium

 1. Duralumin: - It is used to prepare bodies and parts of aircrafts and buses. It is used to prepare Kitchen ware.
 2. Magnalium:- It is used to prepare beams of scientific balances. It is used to prepare household appliances and parts of 

25. Give the important properties of Gun metal.
        1. Gun metal: - It is very strong and resistant to corrosion [destroy gradually by chemical reaction] water and

26. Give physical properties of Alum and Blue Vitriol
        1. Alum: - 1. It is white crystalline compound 2. It is soluble in water and its aqueous solution is acidic.
        2. Blue Vitriol: - 1. It is a blue crystalline Compound 2. It is soluble in water

27.  Give the uses of the following 1.Green Vitriol {ferrous sulphate} 2. Bleaching Powder and 3. Alum
  1. It is used as a mordant in dyeing 2. It is used as an insecticide in agriculture 3. It is used in preparing ink.
  2. It is used for bleaching clothes. 2. It is used paper and textile industries. 3. It is used for disinfecting water.
  3. It is used as a mordant in tanning industry 2. It is used to arrest bleeding 3. It is used in medicine 4. Purification of
      Drinking water.

28Write the names of four alloys of Aluminium and give their compositions
       1. Duralumin: - Aluminium (95%) Copper (4%) Magnesium (1%)and Manganese (small amount)
       2. Magnalium: - Aluminium (90%)Magnesium (10%)
       3. Aluminium Bronze: - Copper (88-96.1%)Aluminium (10.5%) and minute quantities of Iron and Tin
       4. Alnico alloy: - Aluminium, Nickel, Cobalt.

29. What is Efflorescence? Give two examples? Pg No 63

30. What is the double salt made up of potassium and aluminium sulphate commonly called? Write it’s molecular for
      The double salt made up of potassium and aluminium sulphate commonly called Alum.
      Molecular Formula: - K2SO4. Al2 (SO4)3.24H2O

31. The following report is observed in the school health inspection. Name the diseases.

1.    Sathis cannot see in dim light.

       Ans: - Night-Blindness

2. Bleeding of Gums of Udayar.

       Ans: - Scurvey

3 Selva has moon shaped face

      Ans: - Kwashiorker

4 Raja has brittle and weak bones

      Ans: - Rickets Due to the deficiency of Vitamin D

5   Food habits that cause’s facial paralysis

       Ans: -Excessive intake of Vitamin D

31 State the necessary precautions to avoid the following disorders. Pg no 90
      1. Arteriosclerosis 2. To control diabetes 3. Obesity

32. Describe the processes of ammonification and nitrification (March 03)
Ammonification: - The Process by which organic nitrogenous compounds are converted into ammonia by the activity of micro organisms is called ammonification.
Nitrification: - The process in which ammonia is first converted into nitrite and then to nitrate is called nitrification.

33. What is the possible disorder due to excessive or over consumption of Vitamin A in Diet?

1. Dry itchy Skin 2. Painful swelling of legs and hands 3.Thickening of long bones 4. Hyperirritability 5. Enlargement of spleen

34. Disadvantages of excessive intake of nutrients?

Excessive intake of nutrients is wastage of nutrients
Excessive intake of nutrients results in several disorders leading to disability or premature death.

35. State the necessary precautions to avoid high blood pressure.

1. Restricting the consumption of saturated fats.
2. Prevention and Control of obesity.
3. Restriction in intake of salt after the age of 35 years.

36. Suggest the treatment for the following

Kidney disorder: - Kidney disorder can be treated by dialysis and kidney transplantation.
Cancer: - Cancer can be treated by surgery, radiations and chemotherapy.
Diabetes: -
Cretinism: - pg no 107

37. in a medical test, it is found that Sugar is present in the urine of Sathya and Suman.
State the name of the disease Name the hormone causing this disease (March 01)

Ans: - 1. Diabetes   2. Insulin

38. What is diabetes? How is it caused? How is it prevented? Pg no 90

39. Blood Sugar level increase in diabetes? 103

40. State the effect of the following. Pg no 105
1. Effects of x ray on health
2. Effects of Air pollution on human health.
3. Effects of deficiency of iodine on health.
4. Effects of physical and mental strain on health.
5. Effects of consumption of saturated fats on health.

41. Four chemical equation on pg no 126. V.V. Important one will come definitely in the board Exam.

42. Solar energy is essential for bio-chemical cycle
ANS: - The energy required for the operation of different biogeochemical cyclesis obtained from solar energy.
             Therefore, solar energy is essential for bio-chemical cycle

43. Food materials should be covered.
Ans: - Food gets contaminated by micro organisms, if it is not covered.
           Therefore, in order to protect food from contamination it should be covered.

MCHP- Mother Child health programme NREP-National Rural employment Programme

44. (A) Name the hormone secreted by the thyroid gland?
Ans: - The thyroid gland secretes the hormone thyroxine

 (b) Write down four effects due to excess secretion. Or what are the four effects of over secretion of thyroxine.
Ans: - 1. Increased metabolic rate 2. Loss of weight 3.Protruding eyeballs 4. Hyperactivity

45. What are narcotic drugs? Write the names of two narcotic drugs.
Ans: - 1. Narcotic drugs: - The drugs that produce stupor or sleep are called narcotic drugs.
           2. Names of two narcotic drugs: - 1. Morphine             2. L.S.D (Lysergic acid diethylamide)

46. Describe Fermentation? Explain the Fermentation of glucose solution with the help of the balanced   
      equation? State any two types of Fermentation? And also state the two uses of Fermentation? Give its    
Ans: -1. The process in which complex organic compounds are converted into simple organic ones with  
          The help of micro organisms is called fermentation. 2. Fermentation is actually anaerobic respiration  
          By which micro organisms obtain energy required for their life processes. 3. Baker’s yeast which
          Produces the enzyme Zymase is the common fermenting microbe. 4. During Fermentation sugar such as
          Glucose is converted into alcohol and carbon dioxide and energy is released. 5. The overall changes 
          Involved during Fermentation can be represented by the following equation:

          C6H12O6 --------- 2C2H5OH         +       2CO2           Energy
           Glucose            Ethyl alcohol             Carbon

6. Carbon dioxide produced during the process is returned to the atmosphere.

Two types of Fermentation: - 1. Alcoholic fermentation         2. Lactic acid fermentation

Two uses of Fermentation: - 1. The process of fermentation is of great use in the manufacture of alcohol.
2. The curing of tea and tobacco leaves are the other uses of fermentation

By-products are: - 1. Ethyl alcohol          2. Carbon dioxide

47. State any four diseases in children which are controlled by immunization launched by World Health
      Organisation (WHO)
Ans: - 1. Whooping cough 2. Tetanus3. Polio 4. Tuberculosis 5. Measles.

48. Plaster of paris is used in the laboratories for sealing and making the apparatus airtight.
Ans: - 1. When plaster of paris is mixed with proper quantity of water, it hardens. 2. When it hardens it
Expands slightly. 3. Hence, plaster of paris is used for sealing the gaps in the laboratory apparatus,
Where airtight arrangement required.