Class 10 Science: Metals and Non-metals important questions

Metals and Non-metals is a chapter of Class 10 Science for the Andhra Pradesh State Board. These 12 questions are marked Very Important, Important or Practice, and each answer has been checked by our team. Use them to revise, not as a prediction of what will come in the exam.

1. Practice · 1 marks

   1. Name any two metals found in nature as their oxides.

   Aluminium, as bauxite (Al₂O₃·2H₂O), and iron, as haematite (Fe₂O₃). (Manganese also occurs as pyrolusite, MnO₂.)

2. Practice · 1 marks

   2. Write any one physical property of metals.

   Metals are malleable: they can be beaten into thin sheets. (Also: ductile, lustrous, sonorous, good conductors of heat and electricity.)

3. Very Important · 8 marks

   3. Explain the experimental procedure to investigate the conditions under which iron rusts.

   Take three test tubes, A, B and C, each with a clean iron nail. A: add some water and close the tube with a cork (air and water present). B: add boiled distilled water, then a layer of oil on top to keep air out, and cork it (water but no air). C: add anhydrous calcium chloride to absorb moisture and cork it (dry air, no water). Leave them for a few days. Observation: only the nail in tube A rusts. Conclusion: iron needs both air (oxygen) and water (moisture) to rust.

4. Practice · 1 marks

   4. Propose a method to extract a highly reactive metal from its ore.

   Electrolytic reduction: pass electricity through the molten compound. For example, sodium is obtained at the cathode by electrolysing molten sodium chloride. (Carbon cannot reduce such reactive metals.)

5. Practice · 1 marks

   5. Suggest one method to prevent corrosion.

   Painting the iron surface. (Also oiling, greasing, galvanising with zinc, chrome plating or making alloys.)

6. Practice · 1 marks

   6. Which of these is a non-metal? A) Magnesium B) Gold C) Sulphur D) Silver

   C) Sulphur.

7. Important · 4 marks

   7. Describe a neat diagram of the electrolytic refining of copper.

   An electrolytic tank contains acidified copper sulphate solution as the electrolyte. Anode (+): a thick block of impure copper. Cathode (−): a thin strip of pure copper. Both are connected to a battery. When current flows, copper from the anode dissolves into the solution, and an equal amount of pure copper is deposited on the cathode. Insoluble impurities settle below the anode as 'anode mud'.

8. Important · 4 marks

   8. Write any four uses of metals.

   1) Copper and aluminium are used for electric wires (good conductors). 2) Iron is used to make machines, tools, bridges and buildings. 3) Aluminium, copper and steel are used for cooking utensils. 4) Gold and silver are used for jewellery. (Also: aluminium foil for packaging food.)

9. Practice · 1 marks

   9. Ramesh says that all metals are solids at room temperature. What question could you ask to help him reconsider?

   "Which metal is used in a thermometer, and is it solid at room temperature?" Mercury is a metal that is liquid at room temperature. (Gallium and caesium also melt just above room temperature.)

10. Very Important · 8 marks

    10. Explain an activity to show that a more reactive metal displaces a less reactive metal from its compounds.

    1) Take copper sulphate solution (blue) in a test tube. 2) Drop in a clean iron nail (rubbed with sandpaper) and leave it for about 20 minutes. 3) Observation: the blue colour fades to pale green, and a reddish-brown layer of copper forms on the nail. Fe(s) + CuSO₄(aq) → FeSO₄(aq) + Cu(s) Conclusion: iron is more reactive than copper, so it displaces copper from copper sulphate. (Putting copper in iron sulphate gives no reaction.)

11. Practice · 1 marks

    11. A student believes that all metal oxides are basic. He then sees that aluminium oxide reacts with both acids and bases. What should he conclude?

    Not all metal oxides are basic. Some, like aluminium oxide and zinc oxide, are amphoteric: they react with both acids and bases to form salt and water. Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O

12. Very Important · 8 marks

    12. Write an activity to show that metals are good conductors of heat.

    1) Clamp a long aluminium or copper wire horizontally on a stand. 2) Fix a few pins along the wire with wax, at equal distances. 3) Heat the free end of the wire with a spirit lamp. 4) Observation: the wax melts and the pins fall one by one, starting with the pin nearest the flame. Conclusion: heat travels along the metal, so metals are good conductors of heat.