Class 10 Science: Metals and Non-metals important questions

Metals and Non-metals is a chapter of Class 10 Science for the CBSE. These 14 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. On placing a copper coin in a test tube containing green ferrous sulphate solution, it will be observed that the ferrous sulphate solution (a) turns blue, and a grey substance is deposited on the copper coin. (b) turns colourless and a grey substance is deposited on the copper coin. (c) turns colourless and a reddish–brown substance is deposited on the copper coin. (d) remains green with no change in the copper coin.

   (d) Ferrous sulphate solution remains green with no change in the copper coin.

2. Practice · 1 marks

   2. The colour of the solution observed after 30 minutes of placing zinc metal to copper sulphate solution is a) Blue b) Colourless c) Dirty green d) Reddish Brown

   b) Colourless

3. Practice · 1 marks

   3. On adding dilute sulphuric acid to a test tube containing a metal ‘X’, a colourless gas is produced when a burning match stick is brought near it. Which of the following correctly represents metal ‘X’? a) Sodium b) Sulphur c) Copper d) Silver

   a) Sodium

4. Practice · 1 marks

   4. An element with atomic number_____ will form a basic oxide. a) 7 (2,5) b) 17 (2,8,7) c) 14 (2,8,4) d) 11 (2,8,1)

   d) 11 (2,8,1)

5. Practice · 1 marks

   5. An element ‘M' has 50% of the electrons filled in the 3rd shell as in the 2nd shell. The atomic number of ‘M’ is: a) 10 b) 12 c) 14 d) 18

   c) 14

6. Practice · 1 marks

   6. Match column I with column II and select the correct option using the given codes. Column I Column II a. A metal that forms amphoteric oxides (i) Ga b. A metal which melts when kept on our palm (ii) Au c. A metal that reacts with nitric acid (iii) Al d. A metal which cannot displace hydrogen from (iv) Mn acids A. a – (ii), b – (i), c – (iii), d – (iv) B. a – (iii), b – (i), c – (iv), d – (ii) C. a – (iv), b – (ii), c – (iii), d – (i) D. a – (iii), b – (ii), c – (i), d – (iv)

   B. a – (iii), b – (i), c – (iv), d – (ii)

7. Practice · 1 marks

   7. The electronic configuration of three elements X, Y and Z are X- 2, 8, 7; Y- 2, 8, 2; and Z - 2, 8 A. Y and Z are metals B. Y and X are non-metals C. X is a non -metal and Y is a metal D. Y is a non-metal and Z is a metal

   C. X is a non-metal and Y is a metal.

8. Practice · 1 marks

   8. Assertion (A): On adding dil. HCl to a test tube containing a substance ‘X’, a colourless gas is produced which gives a pop sound when a burning match stick is brought near it. Reason (R): In this reaction metal ‘X’ is displaced by Hydrogen. A. Both A and R are true, and R is the correct explanation of A. B. Both A and R are true, and R is not the correct explanation of A. C. A is true but R is false. D. A is false but R is true.

   C. A is true but R is false

9. Important · 3 marks

   9. Give reasons for the following i. Certain metals are used for making cooking utensils. ii. Hydrogen gas does not evolve when certain metals except Mg & Mn react with nitric acid.

   A. Certain metals (like aluminium/ copper) are used for making cooking utensils as they are good conductors of heat and have high melting points. B. Hydrogen gas is not evolved when a metal reacts with nitric acid. This is because HNO3 is a strong oxidising agent. It oxidises the H2 produced to water and itself gets reduced to any of the nitrogen oxides (N 2O, NO, NO2). But magnesium (Mg) and manganese (Mn) react with very dilute HNO3 to evolve H2 gas.

10. Practice · 1 marks

    10. An iron nail is added to each of the two test tubes ‘P’ and ‘Q’ containing aqueous copper (II) sulphate, and aqueous silver nitrate respectively. Which of the following observation is correct? A. In test tube ‘P’ iron nail is coated with a blue coating and in test tube ‘Q’ there is no reaction. B. Iron nail is coated with a brown coating in test tube ‘P’ and silver coating in test tube ‘Q’. C. There is no reaction in either of the test tubes ‘P’ or ‘Q’. D. There is no reaction in test tube ‘P’ but a silver coating on iron nail is seen in test tube ‘Q’.

    B. Iron nail is coated with a brown coating in test tube ‘P’ and silver coating in test tube ‘Q’.

11. Important · 2 marks

    11. The following activity is set-up in the science lab by the teacher. He clamped an aluminium wire on a stand and fixed a pin to the free end of the wire using wax. Then he heated the wire with a burner from the end where the wire is clamped. Students observed the pin fall off. A. If the teacher replaces aluminium wire by silver wire, will the students’ observation change? Justify your answer. B. Will the aluminium wire melt? Give reason for your answer.

    A. The pin will drop but will take less time to drop because silver is a better conductor of heat than aluminium. B. No, aluminium wire will not melt because metals have high melting points.

12. Important · 3 marks

    12. A. An element ‘X’ is stored in kerosene, and cannot be extracted from its ore using a reducing agent. ‘X’ forms an ionic compound on reaction with chlorine. (i) Can we store ‘X’ in water? Give reason to support your answer. (ii) Identify element ‘X’. Name the process used and write the equation for extraction of ‘X’ from its ore. OR B. The domes of many building in Europe are made of copper. These domes now appear greenish in colour. (i) Why do the domes appear greenish though copper is orange-red in colour? (ii) In your opinion, should the copper domes be replaced by iron domes to overcome the problem of change of colour of copper domes? (iii) Domes used to be made from thin sheets of metals. Why did the ancient architects use copper to make domes?

    A. (i) No, ‘X’ is highly reactive and will catch fire. (ii) Sodium. It is extracted from molten sodium chloride by electrolytic reduction Cathode: Na+ + e- → Na Anode: 2Cl- → Cl2 + 2e- (Potassium is also a correct option) OR B. (i) Copper gets oxidised/corroded to basic copper carbonate which is greenish in colour. (ii) No, iron will rust and the reddish layer of rust will come off exposing iron to air, the dome will not be stable. Copper on the other hand on corrosion forms a protective layer which does not allow further corrosion. (iii) Copper is a highly malleable metal, its thin sheets can be used to give different shapes of roofs, like the shape of a dome.

13. Practice · 1 marks

    13. Electrical wires made of aluminum A. corrode easily as aluminium is a very reactive metal. B. corrode easily because porous flaky aluminium oxide is formed. C. do not corrode easily as aluminium oxide forms a protective layer. D. do not corrode easily as aluminium is less reactive than metals like sodium, magnesium and zinc.

    C. do not corrode easily as aluminium oxide forms a protective layer.

14. Very Important · 4 marks

    14. Aavya and Vihan are studying the properties of metals in school. They decide to design and conduct an experiment to test the relative conduction of heat by metals. They use rods of equal length and thickness made of five different metals – A, B, C, D and E. A heat sensor is attached at one end of each rod. The other end of the rod is heated and time required for the heat sensor to beep is noted for all metal rods. The heat sensor at the end of B rod beeps in 10 seconds, C rod in 15 seconds, A a 30 seconds, E in 50 seconds and D sensor beeps in 60 seconds. A. On the basis of the experimental result, which metal is the best conductor of heat? B. Metal G is a better conductor of heat than metal A but it is not as good as metal C. The time taken for the sensor to beep if one of the rods were made of G would have been: (i) 15 s (ii) 20 s (iii) 35 s (iv) 10 s C. The length of all the metal rods is increased by 20% without any change in the thickness. Will the time required for the sensor to beep be affected? How and why? OR D. Mayank tries the experiment with little variation. He keeps the length of all the rods of the same length, but, the thickness of rods is not the same. Will the inference he draws on the basis of his experiment be correct? Justify your answer.

    A. Metal B B. (ii) 20 s C. Yes, the time required for sensor to beep will increase for all the metals. The order of falling of pins will remain the same. Particles vibrate and transfer heat to one another in conduction. Conduction of heat will take more time to travel from one end to the other, as longer distance has to be covered by heat energy. OR D. No, if the thickness of rods is changed the inference will not be correct. The dimensions of the rods have to be the same. A thicker rod will take more time to conduct heat.