Metals & Non-metals - 2 Class 10 Worksheet Science Chapter 3

Q.1. What happens when calcium is treated with water?  (1 Marks)
(i) It does not react with water
(ii) It reacts violently with water
(iii) It reacts less violently with water
(iv) Bubbles of hydrogen gas formed stick to the surface of calcium
(a) (i) and (iv)
(b) (ii) and (iii)
(c) (i) and (ii)
(d) (iii) and (iv)
Q.2. Element A is soft and can be cut with a knife. This is very reactive to air and cannot be kept open in air. It reacts vigorously with water. Identify the element from the following :  (1 Marks)
(a) Mg
(b) Na
(c) P
(d) Ca
Q.3. Give an example of a metal which is the best conductor of heat.  (1 Marks)
Q.4. An element X forms an oxide which turns red litmus blue.
Identify whether X is a metal or non-metal. (1 Marks)
Q.5. Sohan went door to door, posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him, which he dipped in a particular solution. The bangles sparkled like new, but their weight was reduced drastically. The lady was sad, but after a futile argument, the man beat a hasty retreat.
(i) Which of the following is used for dissolution of gold? (1 Marks)
(a) Hydrochloric acid
(b) Sulphuric acid
(c) Nitric acid
(d) Aqua regia
(ii) The composition of aqua-regia is (1 Marks)
(a) Dil. HCl:Conc. HNO₃ 3:1
(b) Conc. HCl:Dil. HNO₃  3:1
(c) Conc. HCl:Conc. HNO₃  3:1
(d) Dil. HCl:Dil. HNO₃ 3:1
 part conc. HNO₃ (3:1).
(iii) Why was the weight of the bangle reduced drastically? (1 Marks)
(iv) Aqua regia is a strong oxidizing agent. (True or False) (1 Marks)
Q.6. Given below are the steps for the extraction of copper from its ore. Write the chemical equation of the reactions involved in each case.
(i) Roasting of copper (i) sulphide
(ii) Reduction of copper (i) oxide from copper (i) sulphide
(iii) Electrolytic refining  (3 Marks)
Q.7. Galvanization is a method of protecting iron from rusting by coating with a thin layer of  (1 Marks)
(a) Gallium
(b) Aluminium
(c) Zinc
(d) Silver
Q.8. Read the passage and answer the following questions.
During extraction of metals, electrolytic refining is used to obtain pure metals. During the process, the impure metal is made the anode, and a thin strip of pure metal is made the cathode. The solution of the metal salt is used as an electrolyte. On passing the current through the electrolyte, the pure metal from the anode dissolves from the electrolyte. An equivalent of pure metal from the electrolyte is deposited on the cathode.
(i) What is the refining of metals? (1 Marks)
(ii) Which of the metals are refined by electrolytic refining? (1 Marks)
I. Au
II. Cu
III. Na
IV. K
(a) I and II
(b) I and III
(c) II and III
(d) II and IV
(iii) During electrolytic refining of zinc, it gets (1 Marks)
(a) deposited on cathode
(b) deposited on anode
(c) deposited on cathode as well as anode
(d) remains in the solution
(iv) In electrolytic refining of copper, ________  (anode/cathode) acts as impure copper, while _________ (anode/cathode) is a strip of pure copper. (1 Marks)
Q.9. State the reason for the following:
(i) Aluminium oxide is called an amphoteric oxide.
(ii) An iron strip dipped in a blue copper sulphate solution turns blue, pale green solution.
(iii) Hydrogen gas is not evolved when most metals react with nitric acid.
(iv) Calcium does not occur in a free state in nature.
(v) Sodium and potassium metals are kept immersed under kerosene.  (5 Marks)
Q.10. Why is carbon not used for reducing aluminium from aluminium oxide? (1 Marks)
Q.11. Name the metal which has a very low melting point and can melt with the heat of your palm?  (1 Marks)
Q.12. Generally, non-metals are not lustrous. Which of the following non-metal is lustrous? (1 Marks)
(a) Sulphur
(b) Oxygen
(c) Nitrogen
(d) Iodine
Q.13. Make a distinction between metals and non-metals with respect to the nature of their oxide.  (1 Marks)
Q.14. (i) Explain the formation of ionic compound CaO with electron dot structure. Atomic numbers of calcium and oxygen are 20 and 8, respectively.
(ii) Name the constituent metals of bronze. (3 Marks) 
Q.15. (a) Define the terms ‘alloy’ and ‘amalgam’. Name the alloy used for welding electric wires together. What are its constituents?
(b) Name the constituents of the following alloys :
(i) Brass
(ii) Stainless steel
(iii) Bronze, 

State one property in each of these alloys, which is different from its main constituents.  (5
Marks)

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