Metals and Non-Metals Important Questions Class 10 Science Chapter 3: Understanding Metals and Non-Metals is essential for Class 10 Science students. Chapter 3 focuses on the physical and chemical properties of metals and non-metals, their reactions with acids, bases, and water, and the extraction and uses of metals.
Practising important questions from Chapter 3- Metals and Non-Metals helps students strengthen key concepts, improve accuracy, and score better in exams. This will help you access well-selected, high-priority questions for Class 10 Science to build a clear understanding, reinforce concepts, and boost exam preparation efficiently.
Metals and Non-Metals Important Questions Class 10 Science Chapter 3 With Solutions
Preparing with these well-selected questions helps you understand the properties, reactions, and uses of elements in Chapter 3. These metals and non-metals class 10 important questions strengthen concepts and boost your overall Science exam performance.
The earthy impurities associated with minerals used in metallurgy are called
(A) Slag
(B) Flux
(C) Gangue
(D) Ore
Ans. (C)
2. A process employed for the concentration of Sulphide ore is
(A) Froth floatation
(B) Roasting
(C) Electrolysis
(D) Bessemerisation
Ans. (A)
3. An iron nail was suspended in CuSO4 solution and kept for a while the solution is
(A) Remained blue, and a coating was found on the nail.
(B) Turned green and a coating was formed on the nail.
(C) Remained blue and no coating was formed on the nail.
(D) Turned green and no coating was formed on the nail.
Ans. (B)
4. Name two metals that are found in nature in the free state.
Sol. Gold and Platinum
5. What chemical process is used for obtaining a metal from its oxide?
Sol. The chemical process that is used for obtaining a metal from its oxide is called reduction. Here, the oxide of the metal will be reduced to the metal with the help of reducing agents or with substitution reactions with another highly reactive metal.
6. Royal water is prepared by mixing two acids 'A' and 'B'. It can dissolve gold and platinum. It is a highly corrosive and fuming liquid. Identify 'A' and 'B'. What is the ratio in which 'A' and 'B' are mixed?
Sol. Acid 'A' is Hydrochloric Acid (HCl) and acid 'B' is Nitric Acid (HNO3). The ratio in which 'A' (HCl) and 'B' (HNO3) are mixed is 3 : 1.
7. Which gas is produced when a metal reacts with dilute hydrochloric acid? Write the chemical reaction when iron reacts with dilute HCl.
Sol. When a metal reacts with dilute hydrochloric acid, hydrogen gas (H2) is produced. The chemical reaction when iron reacts with dilute HCl is as follows:
Fe(s) + 2HCl (dil) → FeCl2 (aq) + H2 (g)
This reaction involves the formation of ferrous chloride salt (FeCl2) and the liberation of hydrogen gas (H2).
8. Why do ionic compounds have high melting points?
Sol. Ionic compounds have a high melting point because of the strong forces of attraction between the oppositely charged cations and anions. Typically, ionic compounds have an equal number of cations and anions that are tightly packed and arranged in a three-dimensional lattice to form their crystalline structures, which also contributes to their high melting points.
9. Name two metals that can displace hydrogen from dilute acids and two metals which cannot do so?
Sol.
• Metals that can displace hydrogen from dilute acids are Sodium and Calcium.
• Metals that cannot displace hydrogen from dilute acids are Copper and Silver.
10. Metals are arranged in the reactivity series. Why is hydrogen kept in the series, though it is not a metal?
Sol. Hydrogen, being a non-metal, is placed in the reactivity series because its reactivity is similar to that of an electropositive element, say metals, i.e. can lose an electron to form positive ion. Since hydrogen has one electron in its valence shell, it can lose its electron and become an electropositive ion (H)+
11. What is the thermit reaction?
Sol. Thermit reactions is highly exothermic displacement reactions between a metal and metal oxide. The heat released in this exothermic reaction is so large that the metal is obtained in its molten state. The most common thermit reaction is between ferric oxide with aluminium metal, which is used to join railway tracks or cracked machine parts. Reaction –
12. Write the equation for the reaction of
(i) Iron with steam
(ii) Calcium and potassium with water
Sol.. (i) Iron with steam
3Fe + 4H2O → Fe3O4 + 4H2
(ii) Calcium with water
Ca + 2H2O → Ca(OH)2 + H2
Potassium with water
2K + 2H2O → 2KOH + H2
13. What are alloys?
Sol. An alloy is a homogeneous mixture of two or more metals, or a metal and a nonmetal. It is prepared by first melting the primary metal, and then dissolving the other elements in it in definite proportions. It is then cooled to room temperature.
Examples – Brass is an alloy of copper and zinc (Cu and Zn), and bronze is an alloy of copper and tin (Cu and Sn).
14. In the electrolytic refining of a metal M, what would you take as the anode, the cathode, and the electrolyte?
Sol.
• Anode – a rod of impure metal M.
• Cathode – thin strips of pure metal M.
• Electrolyte – the salt solution of metal M.
15. A yellow-colored powder 'X' is soluble in carbon disulfide. It burns with a blue flame, forming suffocating-smelling gas which turns moist blue litmus red. Identify 'X' and give a chemical reaction. Identify whether it is a metal or non- metal.
Sol. The yellow-colored powder 'X' is sulfur. Sulfur is soluble in carbon disulfide. Sulfur burns in oxygen with a blue flame to form sulfur dioxide, which has a suffocating smell.
Reaction – S(s) + O2(g) → SO2(g)
SO2 turns moist blue litmus red, as it is acidic in nature. Sulfur is a non-metal.
16. A, B and C are 3 elements that undergo chemical reactions according to the following equations:
a. A2O3 + 2B → B2O3 + 2A
b. 3CSO4 + 2B → B2(SO4)3 + 3C
c. 3CO + 2A → A2O3 + 3C
Answer the following:
(i) Which element is most reactive?
(ii) Which element is least reactive?
Sol.
(i) A more reactive element will replace a lesser reactive element. From reactions (a) and (b), we can say that the most reactive element is B because it can replace both A and C from their compounds.
(ii) From reactions (b) and (c), we can say that element C is the least reactive as it has been replaced both by A and B.
17. You are provided with three metals: sodium, magnesium, and copper. Using only water as the reactant, how will you identify each of them?
Sol. With water as the only reactant, we can distinguish Sodium, Magnesium, and Copper:
a. Sodium reacts vigorously with cold water and burns.
b. Magnesium does not react with cold water, but reacts with hot water and produces hydrogen gas bubbles, and float to the surface.
c. Copper remains unaffected or unreactive with cold and hot water.
18. Give an example of amalgam.
Sol. An alloy, with one of the metals as mercury, is called amalgam. An example of amalgam is the mixture of mercury with silver, which is used to fill dental cavities.
19. What are alkalis? Give one example of alkali.
Sol. Alkalis are bases that are completely soluble in water, or they are the water-soluble hydroxides of metals. Examples – Sodium Hydroxide (NaOH).
20. A group of students looked at different metals and metal sulphate solutions are given in a tabular
(i) Which metal reacted with all other sulphate solutions?
(ii) Which metal did not react with any other metal sulphate solution?
(iii) Arrange the metals in decreasing order of reactivity.
Sol..
(i) Magnesium (Mg) reacted with all other sulphate solutions.
(ii) Copper (Cu) did not react with any other metal sulphate solution.
(iii) The decreasing order of reactivity of metals is Mg > Cr > Co > Cu.
21. Write one point of difference between electrolytic reduction and reduction with carbon. Give one example of each.
Sol. In the case of electrolytic reduction, electrolysis is used for reduction, i.e. the reduction takes place at the cathode by the gain of electrons during electrolysis.
Example –
22. What is corrosion?
Sol. Corrosion is the process that causes damage to the metal, due to the eating up of the surface of the metal when kept exposed to air and moisture for a long time. It is a natural process that results in the transformation of pure metals into undesirable substances when they react with air and water.
23. Give an example of a metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with a knife.
(iii) is the best conductor of heat.
(iv) is a poor conductor of heat.
Sol.
(i) Mercury
(ii) Sodium
(iii) Silver
(iv) Lead
24.
(i) Write the electron-dot structures for sodium, oxygen, and magnesium.
(ii) Show the formation of Na2O and MgO by the transfer of electrons.
(iii) What are the ions present in these compounds?
25. 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:
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.
Sol.
(i) B is the most reactive metal because it displaces the iron from its solution, which is the most reactive of all the elements.
(ii) It is clear that B is more reactive than iron, and since copper is less reactive than iron, B can displace copper from CuSO4.
(iii) The decreasing order of reactivity is B > A >C > D.
26. Read the following and answer any four questions from 10 (i) to 10 (v). According to Arrhenius' theory, acids are substances which dissociate in water to give hydrogen ions H+ (aq) and bases are substances that produce hydroxyl ions OH–(aq). The characteristic property of acid is due to the presence of H+ ions in aqueous solution.
(i) Which of the following is true when HCl (g) is passed through water?
I. It does not ionize in solution.
II. It ionizes in solution.
III. It gives only hydroxyl ions in solution.
IV. It forms hydronium ions in the solution due to the combination of hydrogen ion with water molecule.
(a) I only
(b) III only
(c) II and IV
(d) III and IV
(ii) Which of the following gives the correct increasing order of acidic strength?
(a) water < acetic acid < hydrochloric acid
(b) acetic acid < water < hydrochloric acid
(c) hydrochloric acid < water < acetic acid
(d) water < hydrochloric acid < acetic acid
(iii) Which of the following statements about an aqueous solution of an acid and a base are correct?
I. Higher the pH, the stronger the acid.
II. Higher the pH, the weaker the acid.
III. Lower the pH, the weaker the base.
(iv) Lower the pH, the stronger the base.
(a) I and III
(b) II and III
(c) I and IV
(d) II and IV
(iv) A solution reacts with crushed egg shells to give a gas that turns lime water milky. The
solution contains:
(a) KCl
(b) NaCl
(c) CaCl2
(d) HCl
(v) What happens when a solution of an acid is mixed with a solution of a base in a test tube?
I. The temperature of the solution increases.
II. The temperature of the solution decreases.
III. The temperature of the solution remains the same.
IV. Salt formation takes place.
(a) I only
(b) I and III
(c) II and III
(d) I and IV
Sol.
(i) (c) II and IV
(ii) (a) water < acetic acid < hydrochloric acid
(iii) (b) II and III
(iv) (d) HCl
(v) (d) I and I
27. (a) Observe the diagram given below and answer the following questions:
(i) Name any one metal which should be taken as the metal sample (M) in the boiling tube.
(ii) What is the source of steam in the above shown diagram?
(iii) Write the balanced chemical equation (along with the state symbols) of the reaction between the metal sample (M) and steam.
(b) Name two metals which are stored under kerosene and why?
Sol.. (a)
(i) Aluminium / Iron/Zinc
(ii) Glass wool soaked in water.
(iii) 2Al(s) + 3H2O(g) → Al2O3 (s) + 3H2 (g)/
3Fe(s) + 4H2O(g) → Fe3O4 (s) + 4H2 (g)/
Zn(s) + H2O(g) → ZnO(s) + H2(g)
1 mark for equation and 1 mark for statesymbols.
(b) Na, K, Li (any two)
Metals such as potassium and sodium react so vigorously/violently that they catch fire if kept in the open. Hence, to protect them and to prevent accidental fires, they are kept immersed in kerosene oil.
28. 2 mL of sodium hydroxide solution is added to a few pieces of granulated zinc metal taken in a test tube. When the contents of the test tube are heated, a gas evolves, which is bubbled through a soap solution before testing.
(i) Write the balanced chemical equation of the chemical reaction involved.
(ii) Give a test to detect the gas evolved.
(iii) Which gas will be evolved when the same metal reacts with dilute H2SO4?
Sol.
(i) 2NaOH + Zn + HEAT → Na2ZnO2 + H2
(ii) Test to detect the presence of gas- Bring a burning splinter near the mouth of the test tube, it burns with a pop sound.
(iii) Hydrogen gas will be evolved as zinc is an amphoteric metal which reacts with both acids as well as bases.
29. Case-Based:
Diamond, graphite and fullerenes (such as buckminsterfullerene) are three allotropes of pure carbon. In all three allotropes, the carbon atoms are joined by strong covalent bonds, but in such different arrangements that the properties of the allotropes are very different. Diamond is the hardest substance known, in which each carbon atom is bonded to four other carbon atoms, forming a rigid three-dimensional structure. Graphite is smooth and slippery and also a very good conductor of electricity. Graphite structure is formed by the hexagonal arrays being placed in layers one above the other.
Read the above passage carefully and give the answer of the following questions:
(i) Which of the following is buckminsterfullerene
(a) C-40
(b) C-50
(c) C-60
(d) C-70
Sol. (c) C-60
(ii) What type of bonding is present in diamond?
(a) Ionic
(b) Metallic
(c) Van der Waals
(d) Covalent
Sol.. (d) Covalent
(iii) In graphite, the carbon atoms are arranged in layers of:
(a) hexagonal arrays
(b) pentagonal arrays
(c) heptagonal arrays
(d) octagonal arrays
Sol. (a) hexagonal arrays
(iv) Which among the following is not a property of diamond?
1. It is the hardest substance known
2. It is smooth and slippery
3. It is a poor conductor of electricity
4. It is used as a lubricant
(a) 3. and 4.
(b) 2. and 4.
(c) 1. and 4.
(d) 2., 3. and 4.
Sol.. (b) 2. and 4.
(v) Why is graphite soft and slippery?
(a) Because of its layer-like structure
(b) Because it is made of carbon
(c) Because of its stronger tetrahedron pattern
(d) Because it has free electrons
Sol.. (a) Because of its layer-like structure
30. Case-Based:
Corrosion is the deterioration process of a material due to reactions with its surroundings. Corrosion is a natural process. Just like water flows to the lowest level, all the natural processes tend toward the lowest possible energy states. Corrosion can be defined in many ways. Some definitions are very narrow and deal with a specific form of corrosion while others are quite broad and cover many forms of deterioration. Corrosion's effects in our daily lives are both direct in that corrosion affects the usable service life of our properties, and indirect in that corrosion costs are borne by manufacturers and suppliers of products and services, which they pass on to customers.
Here are few questions, based on it:
(i) Which of the following methods is not used for the prevention of corrosion?
(a) greasing
(b) painting
(c) plating
(d) Heating
Sol. (d)
(ii) Copper gets corroded in presence of:
(a) nitrogen gas
(b) Carbon dioxide gas
(c) Hydrogen sulphide gas
(d) Hydrogen gas
Sol. (b)
(iii) The colour of the layer that deposits on silver ornaments:
(a) green
(b) Blue
(c) black
(d) yellow
Sol. (c)
(iv) Corrosion can be prevented by
(a) alloying
(b) tinning
(c) galvanizing
(d) all of the above
Sol. (d)