NCERT solutions for Science

      NCERT solutions > class 9 > Science > chapter 4  NCERT solution for class 9 // Chapter 4 - Structure of the atom Chapter 4 - Structure of the atom                                    Page number 47  Q1. What are canal rays?  Ans- Canal rays are positively charged radiation with the help of canal rays the positively charged proton and another subatomic particles were discovered Q2. If an atom contains one electron and one proton will it carry any charge or not?   Ans-  If that an atom contain same positive and negative charge then  atom is electrically neutral so the atom is neutral in this condition                      Page number 49  Q3. On the basis of Thomson model of an atom explain how the atom is neutral as a whole Ans-  According to the Th...

  NCERT solutions > class 8 >  science > Chapter 3 NCERT solution for class 8 // Science  // Chapter 3 -  Synthetic fibres and plastics Chapter 3 -  Synthetic fibres and plastics Q1. Explain why some fibres are called synthetic Ans - The fibres which are prepared by man by using chemicals are called synthetic fibre these are made by the joining of small units called monomer to form a long chain of polymer  Example  - Rayon, Nylon, Acrylic, Polyester etc are the synthetic fibres Q2. Mark the correct answer Rayon is different from synthetic fibres because  a) It has a silk like appearance b) It is obtained from wood pulp c) Its fibre can also be woven like those of natural fibres  Ans  - It is obtained from wood pulp Q3. Fill in the blanks with appropriate words a) Synthetic fibres are also called artificial or man made fibres  b) Synthetic fibres are synthesized from raw material called petrochemicals c) Like synthetic fib...

 NCERT solutions  > class 7 > Science >chapter 3 Fibre to fabric  NCERT solution for class 7th  // Science // Chapter  3 - Fibre to fabric Chapter  3 - Fibre to fabric  Q1 . You must be familiar with the following nursery rhymes  a) Baa baa baa baa black sheep have you any wool  . b) Mary had a little lamb whose fleece was white as snow  Answer the following   i) Which part of the Black sheep have wool  ii) What is mean by the white fleece of the lamb  Ans i ) A thin and soft  hair  of the black sheep have a wool   ii ) White fleece means the colour of the fleece is white Q2. The silkworm is( a) a caterpillar ( b)a lava choose the correct option i)  a      ii) b     iii) both a and b   iv) neither a nor b  Ans - Both and b Q3. Which of the following does not yield wool   i) Yak. ii)  Camel.  iii)  Goat   iv) Wo...

  NCERT solutions > class 10 > Science  NCERT solution for class 10th  //Science  // lesson 2  - Acid bases and salt   lesson 2  - Acid bases and salt                     Page number 18 Q1. You have been provided with three test tubes one of them contains distilled water and the other two contain an acidic solution and a basic solution respectively if you are given only red litmus paper how will you identify the contents of each test tube?  Ans- We take a small amount of liquid in three separate test tube  now dip the red litmus paper in each test tube if the liquid turns the red litmus to Blue then  It is the basic solution keep that test tube side and out of these remaining two test tubes at one drop of each  put on the  the same litmus paper which turns blue due to basic solution if that litmus paper turn red then it is the acidic solution and the remai...

  NCERT solutions > class 9 > Science  NCERT solution for class 9th // Science  // Chapter 3 - Atoms and molecules Page number 32.  Q1 . In a reaction 5.3 g of sodium carbonate reacted with 6 gram of ethanoic acid the products were 2.2 gram of carbon dioxide 0.9 gram of water and 8.2 gram of sodium ethanoate show that these observations are  in agreement with the law of conservation of mass sodium carbonate + ethanoic acid  ----- sodium ethanoate + carbon dioxide + water  Ans- . Sodium carbonate + Ethanoic acid_____  Sodium Ethanoate + Carbon dioxide + water    5.3 g.     +.  6g ____ 8.2 +   2.2 g + 0.9 g  11.3g.     ___ 11.3 g  This shows that during the chemical reaction The mass of reactant =  The mass of product  Q2. Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water what mass of Oxygen gas would be required to react completely with 3 gram of ...