CBSE Class 10 Science Chapter-3 Metals and Non-metals Important Questions – Free PDF Download
Free PDF download of Important Questions with Answers for CBSE Class 10 Science Chapter 3 – Metals and Non-metals prepared by expert Science teachers from latest edition of CBSE(NCERT) books only by CoolGyan to score more marks in CBSE board examination.
CBSE Class 10 Science Metals and Non-metals Chapter-3 Important Questions
CBSE Class 10 science Important Questions Chapter 3 – Metals and Non-metals
5 Mark Questions
1. (a) Name a metal which does not stick to glass?
(b) Name a non-metal which is good conductor of electricity?
(c) Name the metal which is commonly used in thermit welding?
(d) What gets deposited at the cathode, a pure or impure metal?
(e) What is the nature of Zinc oxide?
Ans.(i) Mercury
(ii) Graphite
(iii) Aluminum
(iv) A pure metal is always deposited at the cathode
(v) Zinc oxide (ZnO) is an amphoteric oxide.
2. Name three common forms in which metals occur is nature. Explain the interaction between metals and dilute acid?
Ans. The three common forms is which metals occur in nature are
Sulphide form – copper pyrite 
Oxide form – Bauxite 
Carbonate form – Calamine 
Active metals generally interact with dil HCl or dil H2SO4 to evolve hydrogen gas. For eg-
The metals which lie below hydrogen is the activity series do not interact with dilute acid.
3. Sample pieces of five metals A, B, C, D and E were added to the tabulated solutions separately. The results observed are shown in the table:
| Metal |  |  |  |  |  |
| A | No Change | No Change | No Change | Coating on metal | No Change |
| B | Grey Deposit on metal | Brown Coating on metal | No Change | Coating on metal | No Change |
| C | No Change | No Change | No Change | No Change | No Change |
| D | No Change | ———- | No Change | Coating on metal | No Change |
| E | ———– | Brown coating | New coating | New coating | No Change |
Based on the observations recorded in the table, answer the following:
(1) Which is the most reactive metal?
(2) Which is the least reactive metal?
(3) What would be observed if metal D were added to a solution of copper (II) sulphate?
(4) What would be observed if metal E were added to a solution of iron (II) sulphate?
(5) Arrange the metals A, B, C, D and E in decreasing order to their reactivity?
Ans. (a) Na>Ca>Mg>Zn>Cu
(b) (1) Metal reacts violently with cold water and catch fire is sodium.
(2) Metal which evolves H2 gas upon heating with water is magnesium.
(3) Metal which does not react with water on strong heating is copper.
(c) Copper is found in native state.
4. (1) Write electron dot structure for sodium, magnesium and oxygen?
(2) Show formation of 
by the transfer of electrons?
Ans. (1) Atomic No. of Na Z=11
electron dot structure
(2) Mg Z=12
electron dot structure
(3) O Z=8
electron dot structure
(4) Formation of sodium oxide 
Formation of magnesium oxide (MgO)
5. Hydrogen gas is evolved by reacting a piece of magnesium ribbon with water:
(1) Describe how it could be shown that the gas collected is hydrogen.
(2) Write a chemical equation for the reaction taking place between magnesium and water using symbols.
(3) Suggest how the appearance of magnesium would change after a week.
(4) A few drops of universal indicator solution were added to water in the beaker. What colour would expect to see and what pH would this colour indicate?
Ans. (1) If we bring a lighted splint near the gas, it will burn very brightly, accompanied by explosion along with a ‘pop sound’ this show that the gas evolved is hydrogen.
(2) The symbol equation for the reaction is:
(3) After a week’s time, magnesium will lose all its shine and a deposit of magnesium hydroxide will be formed on the surface of the metal.
(4) The indicator will acquire blue colour indicating that the solution is basic. The pH of the solution is expected to be more than seven.
6. Samples of four metals A,B,C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows:
| Metal | Iron(ii)suphate | Copper(ii)sulphate | Zinc sulphate | Silver nitrate |
| A | No reaction | Displacement | ———– | ——— |
| B | Displacement | ————– | No reaction | ——— |
| C | No reaction | No reaction | No reaction | Displacement |
| D | No reaction | No reaction | No reaction | No reaction |
Use the table given above to answer the following questions about metals A,B,C and D.
(i) Which is the most reactive metal?
(ii) What would you observe if B is added to a solution of Copper(II) sulphate?
(iii) Arrange the metals A, B,C and D in order of decreasing reactivity.
Ans.
(i) B is the most reactive metal
(ii)If B is added to a solution of copper (II) sulphate, displacement reaction will take place. Blue colour of copper sulphate will fade and red –brown copper will settle down.
(iii) The decreasing order of reactivity is:
B> A> C >D
7. You are given a hammer, a battery, a bulb, wires and switch.
(a) How could you use them to distinguish between samples of metals and non- metals?
(b) Asses the usefulness of these tests in distinguishing between metals and non- metals?
Ans. (a)Place the sample on an iron block. Strike with hammer. If the sample takes the shape of a sheet, it is a metal. If it breaks into pieces, it is a non-metal.
Set up the arrangement by using a bulb, a battery, wires and switch. Insert the samples of metals and non-metals in the clips one by one and turn the switch on. If the bulb glows, the sample is a metal, if not, then the sample is non-metal.
(b)The above two methods can, in general, be used to distinguish between metals and non-metals.
8. Give reasons:
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminum is highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphides ores are usually converted into oxides during the process of extraction.
Ans. (a) These metals are un-reactive. They do not react with oxygen and other gases present in air and with moisture. Thus, their shine is maintained. That is why these metals are used to make jewellery.
(b) Reaction of sodium, potassium and lithium with oxygen is so violent that they catch fire. To prevent accidental fire, they are stored under kerosene oil.
(c) This is because aluminum is a good conductor of heat. Aluminum forms a layer of aluminum oxide at high temperature which is prevent the further corrosion.
(d) It is easier to reduce oxide than the carbonates and sulphide to the metals.
9. Four metals A, B, C and D are, in turn, added to the following solutions one by one. The observations made are tabulated below:
Answer the following questions based on above information.
(i) Which is the most active metal and why?
(ii) What would be observed if B is added to a solution of copper (II) sulphate and Why?
(iii) Arrange the metals A, B, C and D in order of increasing reactivity.
(iv) Container of which metal can be used to store both zinc sulphate solution and silver nitrate solution.
(v) Which of the above solutions can be easily stored in a container made up of any of these metals?
Ans. (i) B
(ii) Displacement reaction. Because B is more reactive than Cu.
(iii) B.>A>CD
(iv) DI
(v) Zn
