---
title: "Metals and Non-metals: CBSE Class 10 Science previous year questions"
url: https://www.swavid.com/cbse/class-10/science/pyq/metals-and-non-metals
---

# Metals and Non-metals: CBSE Class 10 Science previous year questions

21 questions from CBSE Class 10 board papers, newest first, each with full working.

## CBSE Class 10 Science Question Paper 2026 (Set 31/1/1) with Solutions

### Question 21

*1 mark · MCQ*

Which of the following is a poor conductor of electricity ?

- Pb
- Cu
- Ag
- Al

**Solution**

1. Silver (Ag), copper (Cu), and aluminium (Al) are very good conductors of electricity.
2. Lead (Pb) is a comparatively poor conductor of electricity among metals.

**Answer:** (a) Pb

> Common mistake: Choosing copper or aluminium thinking of common electrical wires while ignoring lead's lower conductivity.

### Question 23

*1 mark · MCQ*

When an element 'X' reacts with water, it starts floating. Identify the element 'X' :

- Potassium
- Calcium
- Sodium
- Iron

**Solution**

1. Calcium reacts with water to form calcium hydroxide and hydrogen gas.
2. The bubbles of hydrogen gas formed stick to the surface of the metal, making it float.

**Answer:** (b) Calcium

> Common mistake: Confusing calcium with sodium or potassium, which float due to hydrogen gas bubbles but react violently and catch fire.

### Question 25

*2 marks · Short answer*

(a) What are amphoteric oxides ?
(b) Categorise the following based on their nature :
$\text{ZnO}, \text{Na}_2\text{O}, \text{CO}_2$

**Part (a)**

1. Metal oxides that show both acidic as well as basic behaviour are known as amphoteric oxides.
2. They react with both acids and bases to form salt and water.

Answer (a): Metal oxides which react with both acids and bases to form salts and water are amphoteric oxides.

**Part (b)**

1. ZnO is an amphoteric oxide.
2. $\text{Na}_2\text{O}$ is a basic oxide because it is a metal oxide.
3. $\text{CO}_2$ is an acidic oxide because it is a non-metal oxide.

Answer (b): ZnO: Amphoteric, $\text{Na}_2\text{O}$: Basic, $\text{CO}_2$: Acidic

**Answer:** ZnO is amphoteric, Na2O is basic, and CO2 is acidic.

> Common mistake: Classifying non-metal oxides as basic or metal oxides as acidic.

### Question 28

*4 marks · Case-based*

Read the following passage and answer the questions given below :
Most of metals occur in combined state in form of ores. Carbonate ores are converted into oxides by calcination and sulphide ores by roasting. Oxides are reduced with suitable reducing agent like carbon to get free metal. Highly reactive metals like Al, Mg are also used as reducing agents to obtain metal from their oxides. Most reactive metals are obtained by electrolytic reduction of their molten ores. Alloying is a very good method of improving the properties of a metal. We can get desired properties by this method. The electrical conductivity and melting point of an alloy is less than that of pure metals.
(a) Why carbonate or sulphide ores are converted into oxides before extraction of metal from it ?
(b) Write a reaction in which Aluminium is used as a reducing agent to obtain metal from its oxide.
(c) (i) How is copper obtained from its ore ($\text{Cu}_2\text{S}$) ? Give equations of the reactions.

**Part (a)**

1. Metal oxides are much easier to reduce to their respective metals than carbonates or sulphides.
2. Therefore, ores are first converted into metal oxides by calcination or roasting before reduction.

Answer (a): Metal oxides are easier to reduce than carbonates or sulphides.

**Part (b)**

1. Aluminium is a highly reactive metal and can displace less reactive metals from their oxides.
2. A well-known example is the thermite reaction where manganese dioxide is reduced by aluminium powder.
3. $3\text{MnO}_2(s) + 4\text{Al}(s) \rightarrow 3\text{Mn}(l) + 2\text{Al}_2\text{O}_3(s) + \text{Heat}$

Answer (b): $3\text{MnO}_2(s) + 4\text{Al}(s) \rightarrow 3\text{Mn}(l) + 2\text{Al}_2\text{O}_3(s) + \text{Heat}$

**Part (c)**

1. Copper(I) sulphide ($\text{Cu}_2\text{S}$) is first heated in air to get some copper(I) oxide.
2. $2\text{Cu}_2\text{S} + 3\text{O}_2(g) \rightarrow 2\text{Cu}_2\text{O}(s) + 2\text{SO}_2(g)$
3. When the supply of air is stopped and the temperature is raised, the remaining copper sulphide reacts with copper oxide to give molten copper.
4. $2\text{Cu}_2\text{O} + \text{Cu}_2\text{S} \rightarrow 6\text{Cu}(s) + \text{SO}_2(g)$

Answer (c): Copper is obtained by roasting partial $\text{Cu}_2\text{S}$ to oxide, followed by self-reduction with remaining $\text{Cu}_2\text{S}$.

**Answer:** Carbonate and sulphide ores are converted to oxides because it is easier to reduce oxide ores than carbonate or sulphide ores to obtain the free metal.

> Common mistake: Writing equations without balancing them or omitting physical states in metallurgical reactions.

### Question 28 (OR)

*2 marks · Case-based*

Read the following passage and answer the questions given below :
Most of metals occur in combined state in form of ores. Carbonate ores are converted into oxides by calcination and sulphide ores by roasting...
(c) (ii) Why highly reactive metals cannot be obtained from their oxides by using carbon as a reducing agent ?
(iii) Why solder, an alloy of lead and tin, is used for welding electrical wires together ?

**Part (c) (ii)**

1. Highly reactive metals like sodium, magnesium, and aluminium have a greater affinity for oxygen than carbon does.
2. Hence, carbon cannot reduce their oxides to free metals.

Answer (c) (ii): Highly reactive metals have more affinity for oxygen than carbon.

**Part (c) (iii)**

1. Solder is an alloy of lead and tin which has a very low melting point.
2. This property makes it suitable for welding electrical wires together.

Answer (c) (iii): Solder has a low melting point, making it ideal for electrical soldering.

**Answer:** Highly reactive metals have a higher affinity for oxygen than carbon, and solder has a low melting point.

> Common mistake: Confusing the reactivity of carbon with that of alkali and alkaline earth metals.

## CBSE Class 10 Science Question Paper 2025 (Set 31/1/1) with Solutions

### Question 2

*1 mark · MCQ*

The products formed when Aluminium and Magnesium are burnt in the presence of air respectively are :

- Al3O4 and MgO2
- Al2O3 and MgO
- Al3O4 and MgO
- Al2O3 and MgO2

**Solution**

1. Aluminium reacts with oxygen in the air to form aluminium oxide, $Al_2O_3$.
2. Magnesium burns in air to form magnesium oxide, $MgO$.

**Answer:** (b) Al2O3 and MgO

> Common mistake: Writing incorrect chemical formulae for metal oxides based on wrong valencies.

### Question 5

*1 mark · MCQ*

Reaction between two elements A and B, forms a compound C. A loses electrons and B gains electrons. Which one of the following properties will not be shown by compound C ?

- It has high melting point.
- It is highly soluble in water.
- It has weak electrostatic forces of attraction between its oppositely charged ions.
- It conducts electricity in its molten state or aqueous solution.

**Solution**

1. Element A loses electrons to form a cation, and B gains electrons to form an anion, forming an ionic compound C.
2. Ionic compounds possess strong electrostatic forces of attraction between oppositely charged ions, not weak forces.

**Answer:** (c) It has weak electrostatic forces of attraction between its oppositely charged ions.

> Common mistake: Assuming ionic bonds are weak because they involve charged ions.

### Question 6

*1 mark · MCQ*

The metals obtained from their molten chlorides by the process of electrolytic reduction are :

- Gold and silver
- Calcium and magnesium
- Aluminium and silver
- Sodium and iron

**Solution**

1. Highly reactive metals like sodium, calcium, and magnesium are obtained by electrolytic reduction of their molten chlorides.
2. Option (b) lists calcium and magnesium, which fit this extraction method.

**Answer:** (b) Calcium and magnesium

> Common mistake: Confusing electrolytic reduction of molten salts with carbon reduction.

### Question 7

*1 mark · MCQ*

The formation of magnesium oxide is correctly shown in option :

- Mg + O -> Mg2+ [O2-]
- Mg -> O -> Mg+ [O-]
- Mg + O -> Mg2+ [O-]2
- 2Mg + O -> [Mg2+]2 [O2-]2

**Solution**

1. Magnesium atom loses two electrons to form $\text{Mg}^{2+}$, and oxygen atom gains two electrons to form $\text{O}^{2-}$.
2. The correct representation for the formation of magnesium oxide involves balanced atoms and resulting ions.

**Answer:** (d) 2Mg + O -> [Mg2+]2 [O2-]2

> Common mistake: Incorrectly balancing the number of electrons transferred or omitting brackets for ions.

### Question 27

*3 marks · Short answer*

(a) "Displacement reactions also play a key role in extracting metals in the middle of the reactivity series." Justify this statement with two examples.
(b) Why can metals high up in the reactivity series not be obtained by reduction of their oxides by carbon ?

**Part a**

1. Highly reactive metals like sodium, calcium, and aluminium are used as reducing agents to displace metals of lower reactivity from their oxides.
2. Example 1: Heating manganese dioxide with aluminium powder: $3MnO_2(s) + 4Al(s) \rightarrow 3Mn(l) + 2Al_2O_3(s) + \text{Heat}$.
3. Example 2: Reaction of iron(III) oxide with aluminium used in thermit welding: $Fe_2O_3(s) + 2Al(s) \rightarrow 2Fe(l) + Al_2O_3(s) + \text{Heat}$.

Answer a: Displacement reactions reduce metal oxides using aluminium powder to obtain metals like manganese and iron.

**Part b**

1. Metals high up in the reactivity series (such as sodium, magnesium, calcium, and aluminium) have a much greater affinity for oxygen than carbon does.
2. Therefore, carbon cannot reduce the oxides of these metals.

Answer b: Carbon cannot reduce oxides of highly reactive metals because these metals have a higher affinity for oxygen than carbon.

**Answer:** Displacement reactions involving more reactive metals like aluminium are used to reduce metal oxides to molten metals, whereas carbon cannot reduce oxides of highly reactive metals because these metals have a higher affinity for oxygen than carbon.

> Common mistake: Writing incorrect chemical formulae or balancing coefficients for the thermit reaction.

### Question 28

*3 marks · Short answer*

(a) With the help of an activity, explain the conditions under which iron articles get rusted.

**Solution**

1. Take three test tubes and label them A, B, and C. Place clean iron nails in each.
2. In test tube A, add some tap water, cork it, and leave it so that nails are exposed to both air and water.
3. In test tube B, add boiled distilled water and about 1 mL of oil to prevent air from dissolving in the water, ensuring the nails are exposed to water only.
4. In test tube C, put anhydrous calcium chloride (a drying agent) to absorb moisture from the air, ensuring the nails are exposed to dry air only.
5. Observe the nails after a few days; rusting occurs only in test tube A where both air and moisture are present, while nails in B and C do not rust.

**Answer:** Iron articles get rusted in the presence of both oxygen and moisture (water vapor).

> Common mistake: Forgetting to mention that both air and moisture are required simultaneously for rusting.

### Question 28 (OR)

*3 marks · Short answer*

(b) (i) Name two metals which react violently with cold water. List any three observations which a student notes when these metal are dropped in a beaker containing water.
(ii) Write a test to identify the gas evolved (if any) during the reaction of these metals with water.

**Part i**

1. Potassium and sodium are the two metals that react violently with cold water.
2. Observation 1: The reaction is highly exothermic and violent.
3. Observation 2: Hydrogen gas evolved immediately catches fire on the surface of water.
4. Observation 3: The metal starts floating because bubbles of hydrogen gas formed stick to its surface.

Answer i: Potassium and sodium react with cold water, releasing hydrogen gas with catching fire and floating due to gas bubbles.

**Part ii**

1. Bring a burning matchstick near the evolved gas.
2. The gas burns with a pop sound, which confirms that the evolved gas is hydrogen.

Answer ii: Hydrogen gas burns with a pop sound when a burning matchstick is brought near it.

**Answer:** Sodium and potassium react violently with cold water, releasing hydrogen gas which catches fire, and the metal floats as it forms bubbles.

> Common mistake: Failing to state all three distinct observations for the metal-water reaction.

## CBSE Class 10 Science Question Paper 2024 (Set 31/1/1) with Solutions

### Question 3

*1 mark · MCQ*

A metal and a non-metal that exists in liquid state at the room temperature are respectively :

- Bromine and Mercury
- Mercury and Iodine
- Mercury and Bromine
- Iodine and Mercury

**Solution**

1. Mercury is the only metal that exists in liquid state at room temperature.
2. Bromine is the only non-metal that exists in liquid state at room temperature.

**Answer:** (c) Mercury and Bromine

> Common mistake: Reversing the order of metal and non-metal as given in the question.

### Question 6

*1 mark · MCQ*

Oxides of aluminium and zinc are :

- acidic
- basic
- amphoteric
- neutral

**Solution**

1. Metal oxides that show both acidic and basic behavior are known as amphoteric oxides.
2. Oxides of aluminium and zinc react with both acids as well as bases to produce salt and water.

**Answer:** (c) amphoteric

> Common mistake: Classifying metal oxides strictly as basic without considering specific exceptions like aluminium and zinc.

### Question 17

*1 mark · Assertion and reason*

Assertion (A) : Hydrogen gas is not evolved when zinc reacts with nitric acid.
Reason (R) : Nitric acid oxidises the hydrogen gas produced to water and itself gets reduced.

- Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
- Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
- Assertion (A) is true, but Reason (R) is false.
- Assertion (A) is false, but Reason (R) is true.

**Solution**

1. Nitric acid is a strong oxidising agent which oxidises the hydrogen gas produced during the reaction to water and gets reduced itself to nitrogen oxides.

**Answer:** Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).

> Common mistake: Thinking that nitric acid behaves like other dilute acids with all metals.

### Question 37

*4 marks · Case-based*

The metals produced by various reduction processes are not very pure. They contain impurities, which must be removed to obtain pure metals. The most widely used method for refining impure metals is electrolytic refining.
(i) What is the cathode and anode made of in the refining of copper by this process ?
(ii) Name the solution used in the above process and write its formula.
(iii) (A) How copper gets refined when electric current is passed in the electrolytic cell ?

**Part (i)**

1. The cathode is made of a thin strip of pure copper.
2. The anode is made of impure copper.

Answer (i): Cathode: pure copper strip; Anode: impure copper block.

**Part (ii)**

1. The solution used is acidified copper sulphate solution.
2. Its chemical formula is $\text{CuSO}_4$.

Answer (ii): Acidified copper sulphate solution, $\text{CuSO}_4$.

**Part (iii)**

1. When electric current is passed, copper ions from the electrolyte go to the cathode and deposit as pure copper.
2. An equivalent amount of copper from the impure anode dissolves into the electrolyte.

Answer (iii): Pure copper from anode dissolves into the electrolyte and deposits on the cathode.

**Answer:** Refining of copper involves pure copper cathode, impure copper anode, and acidified copper sulphate solution.

> Common mistake: Confusing the roles of anode and cathode during electrolytic refining.

### Question 37 (OR)

*2 marks · Case-based*

(iii) (B) You have two beakers 'A' and 'B' containing copper sulphate solution. What would you observe after about $2\text{ hours}$ if you dip a strip of zinc in beaker 'A' and a strip of silver in beaker 'B'? Give reason for your observations in each case.

**Part (iii) (B)**

1. In beaker A, the blue color of copper sulphate fades and a reddish-brown coating appears on the zinc strip because zinc is more reactive than copper and displaces it.
2. In beaker B, no reaction takes place because silver is less reactive than copper and cannot displace it from copper sulphate solution.

Answer (iii) (B): Zinc displaces copper (reaction occurs); silver does not displace copper (no reaction).

**Answer:** Zinc displaces copper from its solution, while silver does not.

> Common mistake: Stating that silver will react with copper sulphate solution.

## CBSE Class 10 Science Question Paper 2023 (Set 31/1/1) with Solutions

### Question 5

*1 mark · MCQ*

A metal 'X' is used in thermite process. When X is burnt in air it gives an amphoteric oxide 'Y'. 'X' and 'Y' are respectively :

- $\text{Fe}$ and $\text{Fe}_2\text{O}_3$
- $\text{Al}$ and $\text{Al}_2\text{O}_3$
- $\text{Fe}$ and $\text{Fe}_3\text{O}_4$
- $\text{Al}$ and $\text{Al}_3\text{O}_4$

**Solution**

1. Aluminium ($\text{Al}$) is used in the thermite process to reduce metal oxides like iron oxide.
2. When burnt in air, aluminium forms aluminium oxide ($\text{Al}_2\text{O}_3$), which is an amphoteric oxide.

**Answer:** (b) $\text{Al}$ and $\text{Al}_2\text{O}_3$

> Common mistake: Confusing iron used in thermite reaction mixture with the metal used as the reducing agent.

### Question 17

*1 mark · Assertion and reason*

Assertion (A) : The colour of aqueous solution of copper sulphate turns colourless when a piece of lead is added to it.
Reason (R) : Lead is more reactive than copper, and hence displaces copper from its salt solution.

- Both (A) and (R) are true and (R) is the correct explanation of (A).
- Both (A) and (R) are true, but (R) is not the correct explanation of (A).
- (A) is true, but (R) is false.
- (A) is false, but (R) is true.

**Solution**

1. Lead is more reactive than copper and displaces copper from copper sulphate solution, forming lead sulphate and copper metal.
2. The blue colour of copper sulphate fades or turns colourless as copper ions are removed from the solution, making both Assertion and Reason true with the Reason being the correct explanation.

**Answer:** "Both (A) and (R) are true and (R) is the correct explanation of (A)."

> Common mistake: Thinking lead is less reactive than copper.

### Question 37

*4 marks · Case-based*

Almost all metals combine with oxygen to form metal oxides. Metal oxides are generally basic in nature. But some metal oxides show both basic as well as acidic behaviour. Different metals show different reactivities towards oxygen. Some react vigorously while some do not react at all.
(a) What happens when copper is heated in air ? (Give the equation of the reaction involved).
(b) Why are some metal oxides categorized as amphoteric ? Give one example.
(c) Complete the following equations :
(i) $\text{Na}_2\text{O}_{(s)} + \text{H}_2\text{O}_{(l)} \rightarrow$
(ii) $\text{Al}_2\text{O}_3 + 2\text{NaOH} \rightarrow$

**Part (a)**

1. When copper is heated in air, it combines with oxygen to form copper(II) oxide, which is a black-coloured coating.
2. The chemical equation for the reaction is: $2\text{Cu}_{(s)} + \text{O}_{2(g)} \xrightarrow{\text{Heat}} 2\text{CuO}_{(s)}$

Answer (a): Copper reacts with oxygen on heating to form black copper(II) oxide ($2\text{CuO}$).

**Part (b)**

1. Metal oxides that react with both acids as well as bases to produce salt and water are known as amphoteric oxides.
2. Example: Aluminium oxide ($\text{Al}_2\text{O}_3$) or Zinc oxide ($\text{ZnO}$).

Answer (b): Metal oxides showing both basic and acidic behaviour are called amphoteric oxides, for example, $\text{Al}_2\text{O}_3$.

**Part (c)(i)**

1. Soluble metal oxides dissolve in water to form alkalis.
2. The completed equation is: $\text{Na}_2\text{O}_{(s)} + \text{H}_2\text{O}_{(l)} \rightarrow 2\text{NaOH}_{(aq)}$

Answer (c)(i): $\text{Na}_2\text{O}_{(s)} + \text{H}_2\text{O}_{(l)} \rightarrow 2\text{NaOH}_{(aq)}$

**Part (c)(ii)**

1. Aluminium oxide reacts with sodium hydroxide to form sodium aluminate and water.
2. The completed equation is: $\text{Al}_2\text{O}_{3(s)} + 2\text{NaOH}_{(aq)} \rightarrow 2\text{NaAlO}_{2(aq)} + \text{H}_2\text{O}_{(l)}$

Answer (c)(ii): $\text{Al}_2\text{O}_{3(s)} + 2\text{NaOH}_{(aq)} \rightarrow 2\text{NaAlO}_{2(aq)} + \text{H}_2\text{O}_{(l)}$

**Answer:** Copper forms a black copper(II) oxide on heating, amphoteric oxides react with both acids and bases, and the completed reactions yield $\text{NaOH}$ and $\text{NaAlO}_2$ respectively.

> Common mistake: Forgetting to balance chemical equations or missing physical states.

### Question 37 (OR)

*2 marks · Case-based*

On burning Sulphur in oxygen a colourless gas is produced.
(i) Write chemical equation for the reaction.
(ii) Name the gas formed.
(iii) State the nature of the gas.
(iv) What will be the action of this on a dry litmus paper?

**Part (i)**

1. Chemical equation: $\text{S}_{(s)} + \text{O}_{2(g)} \rightarrow \text{SO}_{2(g)}$

Answer (i): $\text{S} + \text{O}_2 \rightarrow \text{SO}_2$

**Part (ii)**

1. The colourless gas formed is Sulphur dioxide ($\text{SO}_2$).

Answer (ii): Sulphur dioxide

**Part (iii)**

1. Sulphur dioxide is acidic in nature.

Answer (iii): Acidic

**Part (iv)**

1. There will be no action on dry litmus paper because moisture is required to produce hydrogen ions for the acidic behaviour.

Answer (iv): No action

**Answer:** Sulphur dioxide gas is formed which is acidic in nature but shows no action on dry litmus paper.

> Common mistake: Stating that dry litmus paper turns red, forgetting that water is needed to form acid from acidic gases.

## Related pages

- [Metals and Non-metals: NCERT solutions](https://www.swavid.com/science/class/10/chapter/metals-and-non-metals/ncert-solutions)
- [All CBSE Class 10 Science papers](https://www.swavid.com/cbse/class-10/science/previous-year-papers)

Solutions written by SwaVid, a personal AI tutor for Class 6 to 10 Maths and Science. Practise this chapter free: https://www.swavid.com/start/student