done 8th Science Materials : Metals and Non-metals

• question_answer1)
  Which of the following can be beaten into thin sheets? (a) Zinc                                 (b) Phosphorus              (c) Sulphur                          (d) Oxygen  
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• question_answer2)
  Which of the following statements is correct? (a) All metals are ductile,                           (b) All non-metals are ductile. (c) Generally, metals are ductile,               (d) Some non-metals are ductile.  
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• question_answer3)
  Fill in the blanks. (a) Phosphorus is very ................... non-metal. (b) Metals are ............ conductors of heat and ................. (c) Iron is .............. reactive than copper. (d) Metals react with acids to produce ................ gas.  
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• question_answer4)
  Mark 'T’ if the statement is true and ‘F’ if it is false. (a) Generally, non-metals react with acids. (b) Sodium is a very reactive metal. (c) Copper displaces zinc from zinc sulphate solution. (d) Coal can be drawn into wires.  
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• question_answer5)
  Some properties are listed in the following table. Distinguish between metals and non- metals on the basis of these properties.

  Properties	Metals	Non – metals
  1. Appearance
  2. Hardness
  3. Malleability
  4. Ductility
  5. Heat conduction
  6. Conduction of electricity

   
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• question_answer6)
  Give reasons for the following. (a) Aluminium foils are used to wrap food items. (b) Immersion rods for heating liquids are made up of metallic substances. (c) Copper cannot displace zinc from its salt solution. (d) Sodium and potassium are stored in kerosene.  
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• question_answer7)
  Can you store lemon pickle in an aluminium utensil? Explain.
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• question_answer8)
  In the following table some substances are given in column I. In column II some uses are given. Match the items in column I with the uses in column II. Column I                                                         Column II (i)  Gold                                                      (a) Thermometers (ii) Iron                                                        (b) Electric wire (iii) Aluminium                                             (c) Wrapping food (iv) Carbon                                                   (d) Jewellery (v) Copper                                                    (e) Machinery (vi) Mercury                                                  (f) Fuel  
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• question_answer9)
  What happens when (a) Dilute sulphuric acid is poured on a copper plate? (b) Iron nails are placed in copper sulphate solution? Write word equations of the reactions involved.  
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• question_answer10)
  Saloni took a piece of burning charcoal and collected the gas evolved in a test tube. (a) How will she find the nature of the gas? (b) Write down word equations of all the reactions taking place in this process?  
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• question_answer11)
  One day Reeta went to a Jeweller's shop with her mother. Her mother gave an old gold jewellery to the goldsmith to polish. Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight.
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