THE BUSY BRAINS • BY MANSI SARASWAT
CLASS 10 METALS AND NON-METALS
Important Questions with Answers
Pre-Board & Board Exam Preparation
Class 10 Metals and Non-metals Important Questions with Answers are designed for students preparing for CBSE Class 10 Science Pre-Board and Board Exams. This chapter is an important part of Class 10 Chemistry and covers the properties, reactions, reactivity and extraction of metals as well as the important properties of non-metals.
This complete Class 10 Metals and Non-metals question bank covers physical properties of metals and non-metals, chemical properties, reactions with oxygen, water and acids, displacement reactions, reactivity series, ionic compounds and amphoteric oxides.
It also covers extraction of metals, ores, minerals, gangue, roasting, calcination, reduction, electrolytic reduction, electrolytic refining, corrosion, rusting, galvanisation and alloys.
Use these Class 10 Science important questions for quick revision, NCERT preparation, chemical equations, reaction-based questions, MCQs, case-based questions and Board Exam practice.
1. Physical Properties of Metals and Non-metals
Q1. What are metals?
Metals are elements that generally show properties such as
metallic lustre, malleability, ductility and good conductivity
of heat and electricity.
Q2. What is metallic lustre?
The shining appearance of a freshly cut or polished metal
surface is called metallic lustre.
Q3. What is malleability?
The property of metals by which they can be beaten into thin
sheets is called malleability.
Q4. What is ductility?
The property of metals by which they can be drawn into thin
wires is called ductility.
Q5. What is sonority?
Metals that produce a ringing sound when struck are said to
be sonorous.
Q6. Why are metals generally good conductors of electricity?
Metals contain electrons that can move through the metallic
structure and carry electric charge. Therefore, metals are
generally good conductors of electricity.
Q7. Name one metal which is liquid at room temperature.
Mercury is a metal that is liquid at room
temperature.
Q8. Are all metals hard?
No. Most metals are hard, but some metals such as sodium and
potassium are soft and can be cut with a knife.
Q9. What are non-metals?
Non-metals are elements that generally do not show typical
metallic properties. They are usually poor conductors of heat
and electricity and are neither malleable nor ductile.
Q10. Give two exceptions to the general physical properties
of non-metals.
Graphite is a non-metal that conducts
electricity. Iodine is a lustrous non-metal.
| Metals | Non-metals |
|---|---|
| Generally lustrous. | Generally non-lustrous. |
| Generally malleable. | Generally non-malleable. |
| Generally ductile. | Generally non-ductile. |
| Generally good conductors. | Generally poor conductors. |
| Generally sonorous. | Generally non-sonorous. |
2. Chemical Properties of Metals
Q11. Why do metals react with other elements?
Metals tend to attain a stable electronic configuration by
losing electrons. Therefore, they react with other elements
to form compounds and ions.
Q12. What type of ions are generally formed by metals?
Metals generally lose electrons and form
positively charged ions called cations.
Q13. What happens when metals react with oxygen?
Metals generally react with oxygen to form
metal oxides.
Metal + Oxygen → Metal Oxide
Q14. What is the nature of most metal oxides?
Most metal oxides are basic in nature.
However, some oxides such as aluminium oxide and zinc oxide
are amphoteric.
Q15. What are amphoteric oxides?
Metal oxides that react with both acids and bases to produce
salt and water are called amphoteric oxides.
Q16. Give two examples of amphoteric oxides.
Aluminium oxide (Al2O3)
and zinc oxide (ZnO).
Al2O3 + 6HCl
→ 2AlCl3 + 3H2O
Al2O3 + 2NaOH → 2NaAlO2 + H2O
Al2O3 + 2NaOH → 2NaAlO2 + H2O
3. Metals with Oxygen – Important Questions
Q17. Write the reaction between copper and oxygen.
Copper reacts with oxygen on heating to form black copper(II)
oxide.
2Cu + O2 → 2CuO
Q18. Write the reaction between aluminium and oxygen.
4Al + 3O2 → 2Al2O3
Q19. Why is sodium kept immersed in kerosene oil?
Sodium is highly reactive and reacts vigorously with oxygen
and moisture. It is therefore stored under kerosene oil to
prevent its contact with air and water.
Q20. Why does aluminium not corrode easily even though it is
a reactive metal?
Aluminium reacts with oxygen and forms a thin, protective
layer of aluminium oxide on its surface. This layer prevents
further oxidation of the metal.
Q21. Which metals do not react easily with oxygen?
Silver and gold do not react with oxygen even at high
temperatures. Copper is also much less reactive towards
oxygen than metals such as sodium or magnesium.
⭐ Board Tip:
Learn the difference between a metal being
highly reactive and being
protected by an oxide layer. Aluminium is a
favourite conceptual example. :chatgpt-content-reference{index="3"}
4. Metals with Water – Important Questions
Q22. What happens when metals react with water?
Depending on the metal, reaction with water may produce a
metal hydroxide or metal oxide along with hydrogen gas.
Metal + Water → Metal Oxide / Metal Hydroxide + Hydrogen
Q23. What happens when sodium reacts with cold water?
Sodium reacts very vigorously with cold water and forms
sodium hydroxide and hydrogen gas.
2Na + 2H2O
→ 2NaOH + H2 + Heat
Q24. Why does potassium and sodium react violently with water?
Potassium and sodium are highly reactive metals. Their
reactions with water are highly exothermic and may produce
enough heat for the hydrogen formed to catch fire.
Q25. Write the reaction between calcium and water.
Ca + 2H2O
→ Ca(OH)2 + H2
Q26. Why does calcium start floating on water?
Hydrogen gas bubbles produced during the reaction stick to
the surface of calcium. These bubbles make calcium float.
Q27. How does magnesium react with water?
Magnesium does not react appreciably with cold water. It
reacts with hot water to form magnesium hydroxide and
hydrogen. It also reacts with steam.
Q28. Which metals react with steam?
Aluminium, iron and zinc react with steam to form their
respective oxides and hydrogen.
2Al + 3H2O(g)
→ Al2O3 + 3H2
3Fe + 4H2O(g) → Fe3O4 + 4H2
3Fe + 4H2O(g) → Fe3O4 + 4H2
Q29. Which metals do not react with water?
Metals such as lead, copper, silver and gold do not react
with water under ordinary conditions.
5. Metals with Acids – Important Questions
Q30. What happens when a reactive metal reacts with dilute acid?
Reactive metals generally react with dilute acids to form
a salt and hydrogen gas.
Metal + Dilute Acid → Salt + Hydrogen
Q31. Write the reaction of iron with dilute sulphuric acid.
Fe + H2SO4
→ FeSO4 + H2
Q32. Which gas is produced when a reactive metal reacts with
dilute hydrochloric acid?
Hydrogen gas is produced.
Q33. Do all metals react with dilute acids?
No. Metals below hydrogen in the activity series generally
do not displace hydrogen from dilute non-oxidising acids.
Q34. Name two metals that can displace hydrogen from dilute acids.
Zinc and iron are examples of metals that
can displace hydrogen from dilute acids.
Q35. Name two metals that do not displace hydrogen from
dilute acids.
Copper and silver do not displace hydrogen
from dilute acids.
6. Displacement Reactions – Important Questions
Q36. What is a displacement reaction?
A displacement reaction is a reaction in which a more reactive
element displaces a less reactive element from its compound.
Metal A + Salt of Metal B
→ Salt of Metal A + Metal B
if A is more reactive than B
if A is more reactive than B
Q37. What happens when zinc is added to iron(II) sulphate solution?
Zinc is more reactive than iron, so it displaces iron from
iron(II) sulphate.
Zn + FeSO4
→ ZnSO4 + Fe
Q38. What happens when copper is placed in iron sulphate solution?
No displacement reaction occurs because copper is less
reactive than iron.
Q39. What happens when copper is added to silver nitrate solution?
Copper is more reactive than silver and displaces silver.
Cu + 2AgNO3
→ Cu(NO3)2 + 2Ag
Q40. How can displacement reactions be used to compare
reactivity of metals?
If metal A displaces metal B from B's salt solution, then
A is more reactive than B. Repeated displacement experiments
can therefore be used to arrange metals in decreasing order
of reactivity.
7. Reactivity Series – Very Important
Q41. What is the reactivity series?
The reactivity series is a list of metals arranged in
decreasing order of their chemical reactivity.
K → Na → Ca → Mg → Al → Zn → Fe → Pb → H → Cu → Hg → Ag → Au
Most Reactive → Least Reactive
Most Reactive → Least Reactive
Q42. Which is the most reactive metal in the NCERT activity series?
Potassium (K).
Q43. Which is the least reactive metal among the metals
shown in the NCERT activity series?
Gold (Au).
Q44. Why is hydrogen included in the activity series?
Hydrogen provides a reference point for comparing whether a
metal can displace hydrogen from dilute acids. Metals above
hydrogen can generally displace it from dilute acids.
Q45. Which metals can displace hydrogen from dilute acids?
Metals placed above hydrogen in the reactivity series can
generally displace hydrogen from dilute acids.
Q46. Which metals are found in free state in nature?
Very less reactive metals such as gold, silver,
platinum and copper may be found in the free state.
⭐ Memorise this order:
K Na Ca Mg Al Zn Fe Pb H Cu Hg Ag Au
This single sequence helps solve questions involving displacement reactions, reactions with acids, extraction methods and relative reactivity. :chatgpt-content-reference{index="4"}
K Na Ca Mg Al Zn Fe Pb H Cu Hg Ag Au
This single sequence helps solve questions involving displacement reactions, reactions with acids, extraction methods and relative reactivity. :chatgpt-content-reference{index="4"}
8. Ionic Compounds – Important Questions
Q47. How are ionic compounds formed?
Ionic compounds are formed by the transfer of electrons
from one atom to another, usually from a metal to a non-metal.
The resulting oppositely charged ions are held together by
strong electrostatic forces of attraction.
Q48. What ions are present in sodium chloride?
Sodium chloride contains Na+ and
Cl− ions.
Q49. What are the main properties of ionic compounds?
Ionic compounds are generally hard and brittle, have high
melting and boiling points, are generally soluble in water
and conduct electricity in molten state or aqueous solution.
Q50. Why do ionic compounds have high melting points?
Ionic compounds contain oppositely charged ions held together
by strong electrostatic forces. A considerable amount of
energy is required to overcome these forces.
Q51. Why do ionic compounds conduct electricity in molten
state but not in solid state?
In the solid state, ions are fixed in their positions and
cannot move freely. In the molten state, the ions become
free to move and can therefore conduct electricity.
Q52. Why are ionic compounds generally brittle?
When pressure is applied, layers of ions can shift so that
similarly charged ions come close to each other. Strong
repulsion then causes the crystal to break.
Q53. Show the formation of sodium oxide by electron transfer.
Two sodium atoms each lose one electron and oxygen gains
two electrons.
2Na → 2Na+ + 2e−
O + 2e− → O2−
2Na+ + O2− → Na2O
O + 2e− → O2−
2Na+ + O2− → Na2O
Q54. Show the formation of magnesium oxide by electron transfer.
Magnesium loses two electrons and oxygen gains two electrons.
Mg → Mg2+ + 2e−
O + 2e− → O2−
Mg2+ + O2− → MgO
O + 2e− → O2−
Mg2+ + O2− → MgO
9. Extraction of Metals – Metallurgy
Q55. What are minerals?
Elements or compounds that occur naturally in the earth's
crust are called minerals.
Q56. What are ores?
Minerals from which metals can be extracted profitably are
called ores.
Q57. What is gangue?
The unwanted impurities such as soil and sand associated
with an ore are collectively called gangue.
Q58. What is metallurgy?
The extraction of metals from their ores followed by
purification or refining is called metallurgy.
ORE
↓
Enrichment of Ore
↓
Conversion to Suitable Compound
↓
Reduction
↓
Refining
↓
PURE METAL
↓
Enrichment of Ore
↓
Conversion to Suitable Compound
↓
Reduction
↓
Refining
↓
PURE METAL
Q59. Why are metals low in the activity series often found
in the free state?
Metals low in the activity series are less reactive and
therefore do not readily combine with other elements.
Some of them can consequently occur in the free state.
Q60. How are metals low in the activity series extracted?
Their compounds can often be reduced by heating. For example,
the oxide of mercury can be reduced to mercury by heating.
Q61. What is roasting?
The process of heating sulphide ores strongly in the presence
of excess air to convert them into oxides is called
roasting.
2ZnS + 3O2
→ 2ZnO + 2SO2
Roasting
Roasting
Q62. What is calcination?
The process of heating carbonate ores strongly in limited
air to convert them into oxides is called
calcination.
ZnCO3
→ ZnO + CO2
Calcination
Calcination
Q63. Why are sulphide and carbonate ores converted into oxides?
It is generally easier to obtain a metal from its oxide than
from its sulphide or carbonate. Therefore, sulphide ores are
roasted and carbonate ores are calcined to convert them into
oxides before reduction.
Q64. How is zinc obtained from zinc oxide?
Zinc oxide is reduced using carbon.
ZnO + C → Zn + CO
Q65. Why can't highly reactive metals be extracted using carbon?
Highly reactive metals have a greater affinity for oxygen
than carbon. Therefore, carbon cannot reduce their oxides
effectively.
Q66. How are highly reactive metals such as sodium,
magnesium and calcium obtained?
They are obtained by electrolytic reduction
of their molten compounds, such as molten chlorides.
Q67. What is the thermit reaction?
The highly exothermic reaction in which aluminium reduces
iron(III) oxide to molten iron is called the
thermit reaction.
Fe2O3 + 2Al
→ 2Fe + Al2O3 + Heat
Q68. Give one important use of the thermit reaction.
The thermit reaction is used for joining railway tracks
and repairing cracked machine parts.
10. Electrolytic Refining of Metals
Q69. Why is refining of metals necessary?
Metals obtained from ores by different extraction methods
usually contain impurities. Refining is necessary to obtain
metal of high purity.
Q70. What is electrolytic refining?
Electrolytic refining is a method of purifying a metal using
electrolysis. It is used for metals such as copper, zinc,
tin, nickel, silver and gold.
Q71. In electrolytic refining, what is used as the anode?
The impure metal is used as the anode.
Q72. What is used as the cathode during electrolytic refining?
A thin strip of pure metal is used as the cathode.
Q73. What is the electrolyte used in electrolytic refining?
A solution of a suitable salt of the metal is used as the
electrolyte. For copper, acidified copper sulphate solution
is used.
Q74. What is anode mud?
Insoluble impurities settle at the bottom of the anode during
electrolytic refining. These are called
anode mud.
Impure Metal = ANODE
↓
Metal ions enter electrolyte
↓
Pure Metal deposits on CATHODE
↓
Insoluble impurities → ANODE MUD
↓
Metal ions enter electrolyte
↓
Pure Metal deposits on CATHODE
↓
Insoluble impurities → ANODE MUD
11. Corrosion and Prevention of Corrosion
Q75. What is corrosion?
The gradual deterioration of a metal due to its reaction
with substances present in the environment is called
corrosion.
Q76. What is rusting?
The corrosion of iron in the presence of moist air produces
a brown flaky substance called rust. This process is known
as rusting.
Q77. What conditions are necessary for rusting of iron?
Iron rusts when both oxygen and water/moisture
are available.
NCERT Rusting Experiment – Important Observation
Test Tube A: Iron nail exposed to air and water → rust forms.
Test Tube B: Boiled water covered with oil → air is prevented from dissolving in water → no rust.
Test Tube C: Dry air with anhydrous calcium chloride → moisture removed → no rust.
Q78. How can corrosion be prevented?
Corrosion can be prevented by methods such as
painting, oiling, greasing, galvanisation, chrome
plating, anodising and alloying.
Q79. What is galvanisation?
Galvanisation is the process of protecting iron or steel
from rusting by coating it with a thin layer of zinc.
Q80. Why is galvanisation useful even if the zinc coating
gets scratched?
Zinc is more reactive than iron and can provide sacrificial
protection to the underlying iron. Therefore, the iron can
remain protected even when the coating is damaged.
Q81. How can copper vessels develop a green coating?
Copper reacts slowly with moist carbon dioxide in air and
forms a green coating of basic copper carbonate.
Q82. Why do silver articles become black?
Silver reacts with sulphur compounds present in air and
forms a black coating of silver sulphide.
12. Alloys – Important Questions
Q83. What is an alloy?
An alloy is a homogeneous mixture of two or more metals,
or a metal and a non-metal.
Q84. Why are alloys made?
Alloying can change the properties of metals and can produce
materials with desired properties such as greater hardness,
strength or corrosion resistance.
Q85. What are the constituents of brass?
Brass is an alloy of copper and zinc.
Q86. What are the constituents of bronze?
Bronze is an alloy of copper and tin.
Q87. What is solder?
Solder is an alloy of lead and tin. It has a
relatively low melting point and is used for joining
electrical wires.
Q88. Why is pure gold not generally used for making jewellery?
Pure gold is very soft. It is therefore alloyed with metals
such as silver or copper to make it harder and more suitable
for jewellery.
Q89. What is stainless steel?
Stainless steel is an alloy of iron with elements such as
chromium and nickel. It is hard and resistant to rusting.
| Alloy | Constituents | Important Property / Use |
|---|---|---|
| Brass | Copper + Zinc | Used for various utensils and fittings. |
| Bronze | Copper + Tin | Hard alloy with useful applications. |
| Solder | Lead + Tin | Low melting point; used for joining wires. |
| Stainless Steel | Iron + Chromium + Nickel | Hard and resistant to corrosion. |
13. Chemical Properties of Non-metals
Q90. What type of ions do non-metals generally form?
Non-metals generally gain electrons and form
negatively charged ions called anions.
Q91. What type of oxides are generally formed by non-metals?
Non-metals generally form acidic or neutral oxides
when they combine with oxygen.
Q92. Do non-metals displace hydrogen from dilute acids?
No. Non-metals generally do not displace hydrogen from
dilute acids.
Q93. How do non-metals react with hydrogen?
Non-metals can react with hydrogen to form covalent hydrides.
Q94. What happens when sulphur is heated in air?
Sulphur burns in air to form sulphur dioxide.
S + O2 → SO2
Q95. What happens when sulphur dioxide dissolves in water?
Sulphur dioxide reacts with water to form sulphurous acid,
making the solution acidic.
SO2 + H2O → H2SO3
Q96. Why does moist blue litmus turn red when exposed to
sulphur dioxide?
Sulphur dioxide dissolves in moisture and forms sulphurous
acid. The acidic solution turns moist blue litmus red.
Q97. Give one important exception to the poor electrical
conductivity of non-metals.
Graphite, an allotrope of carbon, conducts
electricity.
14. Important Diagrams and Process Questions
Diagram Q1. Draw and label the electrolytic refining
of copper.
Important labels: impure copper anode, pure copper cathode, acidified copper sulphate solution and anode mud.
Diagram Q2. Draw the activity-series related
metallurgy flowchart.
Show highly reactive, moderately reactive and low-reactivity metals and their corresponding extraction methods.
Diagram Q3. Draw the rusting experiment using
three test tubes.
Label Test Tube A with air + water, Test Tube B with boiled water + oil and Test Tube C with dry air + anhydrous calcium chloride.
Diagram Q4. Show electron transfer in the formation
of NaCl.
Show sodium losing one electron and chlorine gaining one electron to form Na+ and Cl−.
Diagram Q5. Show electron transfer in MgO.
Show magnesium losing two electrons and oxygen gaining two electrons.
Diagram Q6. Draw the thermit process.
Show Fe2O3 and aluminium reacting to produce molten iron and aluminium oxide.
🎯 Diagram Practice Tip:
Practise diagrams with labels. In chemistry questions,
correct labels and chemical equations can make a major
difference in scoring.
15. NCERT-Based Board Questions
Q98. Which pair will give a displacement reaction:
MgCl2 + Al or AgNO3 + Cu?
AgNO3 solution and copper metal
will give a displacement reaction because copper is more
reactive than silver.
Q99. Which methods can be used to prevent rusting of an
iron frying pan?
Painting, greasing or coating the iron with zinc can
prevent contact with moisture and help prevent rusting.
Q100. An element reacts with oxygen to give a compound with
a high melting point that is soluble in water. Which element
could it be: calcium, carbon, silicon or iron?
Calcium is the most appropriate option
because calcium oxide is an ionic compound with a high
melting point and reacts with water to form calcium hydroxide.
Q101. Why are food cans coated with tin and not zinc?
Zinc is more reactive than tin. Tin is therefore preferred
for coating food cans because it is less reactive under
ordinary conditions.
Q102. How can a battery, bulb, wires and a switch be used
to distinguish metals from non-metals?
Place the sample in a simple circuit. If the bulb glows,
the sample conducts electricity. Most metals conduct
electricity, while most non-metals do not. However,
exceptions such as graphite must be considered.
Q103. Name two metals that will displace hydrogen from
dilute acids and two that will not.
Zinc and iron can displace hydrogen. Copper and silver
cannot displace hydrogen from dilute acids.
Q104. Explain the process of electrolytic refining.
The impure metal is made the anode and a thin strip of pure
metal is made the cathode. A solution of the metal salt is
used as electrolyte. On passing electric current, pure metal
from the anode dissolves into the electrolyte and an equivalent
amount is deposited on the cathode. Insoluble impurities settle
as anode mud.
Q105. State two ways of preventing rusting of iron.
Painting and galvanisation are two methods.
Oiling, greasing, chrome plating and alloying are also used.
Q106. Why are platinum, gold and silver used for making jewellery?
They are lustrous and comparatively less reactive. They do
not corrode easily and retain their appearance for a long time.
Q107. Why are sodium, potassium and lithium stored under oil?
These metals are highly reactive and can react vigorously
with oxygen and moisture. Storing them under oil prevents
contact with air and water.
Q108. Why is aluminium used to make cooking utensils even
though it is highly reactive?
Aluminium develops a protective layer of aluminium oxide
on its surface. This layer prevents further corrosion and
makes aluminium useful for many applications.
Q109. Why are carbonate and sulphide ores usually converted
into oxides during extraction?
Metal oxides are generally easier to reduce to metals than
the corresponding carbonates and sulphides. Therefore,
carbonate ores are calcined and sulphide ores are roasted
before reduction.
Q110. Why is copper used for hot-water tanks instead of iron?
Copper is less reactive and does not react readily with
water, while iron is more reactive and can corrode under
suitable conditions.
16. Important MCQs – Metals and Non-metals
Q111. Which metal is liquid at room temperature?
A. Sodium
B. Mercury
C. Aluminium
D. Iron
Answer: B. Mercury
Q112. The property by which metals can be drawn into wires is:
A. Malleability
B. Ductility
C. Sonority
D. Lustre
Answer: B. Ductility
Q113. Which of the following is an amphoteric oxide?
A. Na2O
B. CO2
C. Al2O3
D. SO2
Answer: C. Al2O3
Q114. Which metal is stored under kerosene?
A. Copper
B. Gold
C. Sodium
D. Silver
Answer: C. Sodium
Q115. Which gas is evolved when zinc reacts with dilute HCl?
A. Oxygen
B. Hydrogen
C. Nitrogen
D. Carbon dioxide
Answer: B. Hydrogen
Q116. Which metal can displace copper from copper sulphate solution?
A. Silver
B. Gold
C. Zinc
D. Platinum
Answer: C. Zinc
Q117. Which metal is the most reactive among the following?
A. Cu
B. Ag
C. Zn
D. Au
Answer: C. Zn
Q118. Ionic compounds conduct electricity in molten state because:
A. Electrons become free
B. Ions become free to move
C. Atoms become neutral
D. Molecules disappear
Answer: B. Ions become free to move
Q119. Conversion of sulphide ore into oxide by heating in
excess air is called:
A. Calcination
B. Roasting
C. Reduction
D. Refining
Answer: B. Roasting
Q120. Conversion of carbonate ore into oxide by heating in
limited air is called:
A. Roasting
B. Calcination
C. Electrolysis
D. Galvanisation
Answer: B. Calcination
Q121. Which process is used for refining copper?
A. Distillation
B. Electrolytic refining
C. Filtration
D. Sublimation
Answer: B. Electrolytic refining
Q122. The impure metal is used as which electrode in
electrolytic refining?
A. Cathode
B. Anode
C. Both
D. Neither
Answer: B. Anode
Q123. The insoluble impurities collected during electrolytic
refining are called:
A. Gangue
B. Slag
C. Anode mud
D. Flux
Answer: C. Anode mud
Q124. Which process protects iron by coating it with zinc?
A. Alloying
B. Galvanisation
C. Roasting
D. Calcination
Answer: B. Galvanisation
Q125. Brass is an alloy of:
A. Cu + Zn
B. Cu + Sn
C. Pb + Sn
D. Fe + Cr
Answer: A. Cu + Zn
Q126. Bronze is an alloy of:
A. Cu + Zn
B. Cu + Sn
C. Fe + C
D. Pb + Sn
Answer: B. Cu + Sn
Q127. Which non-metal is a good conductor of electricity?
A. Sulphur
B. Phosphorus
C. Graphite
D. Oxygen
Answer: C. Graphite
Q128. Which metal is obtained by electrolytic reduction?
A. Sodium
B. Copper
C. Iron
D. Zinc
Answer: A. Sodium
Q129. Rusting of iron requires:
A. Only oxygen
B. Only water
C. Oxygen and water
D. Nitrogen and water
Answer: C. Oxygen and water
Q130. Which of the following is an alloy?
A. Copper
B. Iron
C. Brass
D. Aluminium
Answer: C. Brass
17. Case-Based Questions – Metals and Non-metals
Case Study 1 – Reactivity Series
Four metals A, B, C and D were tested against different salt solutions. Metal A displaced copper, metal B displaced iron, metal C displaced silver, while metal D did not show displacement in the tested solutions.
(a) What does a displacement reaction indicate?
It indicates that the displacing metal is more reactive
than the displaced metal.
(b) Which metal should be placed higher in the activity series:
a metal that displaces iron or one that only displaces silver?
A metal that displaces iron is more reactive than iron and
would generally be placed higher than a metal that only
displaces silver.
(c) What is the key rule for displacement?
A more reactive metal displaces a less reactive metal
from its salt solution.
Case Study 2 – Rusting of Iron
Three test tubes contain iron nails under different conditions. One contains air and water, another contains boiled water covered with oil, and the third contains dry air with anhydrous calcium chloride.
(a) In which test tube will rust form?
The test tube containing both air and water.
(b) Why does boiled water covered with oil prevent rusting?
Boiling removes dissolved air and the oil layer prevents
air from dissolving again in the water.
(c) What does anhydrous calcium chloride do?
It absorbs moisture and keeps the air dry.
Case Study 3 – Extraction of Metals
Metals are extracted from ores using methods based on their position in the activity series. Highly reactive metals require electrolysis, while moderately reactive metals can often be obtained by reduction of their oxides.
(a) Why are highly reactive metals extracted by electrolysis?
Their compounds are too stable to be reduced effectively
by carbon.
(b) What is roasting?
Heating a sulphide ore strongly in excess air to convert
it into an oxide.
(c) What is calcination?
Heating a carbonate ore strongly in limited air to convert
it into an oxide.
Case Study 4 – Ionic Compounds
Sodium loses an electron while chlorine gains an electron. The resulting ions combine to form sodium chloride.
(a) What ion is formed by sodium?
Na+.
(b) What ion is formed by chlorine?
Cl−.
(c) Why does sodium chloride conduct electricity in molten state?
Its ions are free to move in the molten state and can
carry electric charge.
Case Study 5 – Alloys
Pure iron is relatively soft and is not generally used in its pure form for many engineering applications. Alloying changes the properties of metals.
(a) What is an alloy?
A homogeneous mixture of two or more metals, or a metal
and a non-metal.
(b) Name the alloy of iron, chromium and nickel.
Stainless steel.
(c) Why is stainless steel useful?
It is hard and resistant to corrosion.
18. Metals and Non-metals – Quick Revision
| Concept | Quick Revision |
|---|---|
| Malleability | Ability to be beaten into thin sheets. |
| Ductility | Ability to be drawn into wires. |
| Sonority | Production of ringing sound when struck. |
| Amphoteric Oxide | Oxide that reacts with both acids and bases. |
| Displacement Reaction | More reactive metal displaces a less reactive metal. |
| Reactivity Series | K → Na → Ca → Mg → Al → Zn → Fe → Pb → H → Cu → Hg → Ag → Au. |
| Mineral | Naturally occurring element or compound in the earth's crust. |
| Ore | Mineral from which metal can be extracted profitably. |
| Gangue | Unwanted impurities associated with an ore. |
| Roasting | Heating sulphide ore in excess air. |
| Calcination | Heating carbonate ore in limited air. |
| Thermit Reaction | Aluminium reduces iron(III) oxide to molten iron. |
| Electrolytic Refining | Purification of metals using electrolysis. |
| Corrosion | Gradual deterioration of a metal by environmental reactions. |
| Rusting | Corrosion of iron in presence of oxygen and moisture. |
| Galvanisation | Coating iron or steel with zinc. |
| Brass | Copper + Zinc. |
| Bronze | Copper + Tin. |
| Solder | Lead + Tin. |
| Stainless Steel | Iron alloy containing chromium and nickel. |
✅ Class 10 Board Exam Final Checklist
- ✔ I can define malleability, ductility and sonority.
- ✔ I know the physical properties of metals and non-metals.
- ✔ I know the important exceptions to these properties.
- ✔ I can write reactions of metals with oxygen.
- ✔ I can write reactions of metals with water.
- ✔ I can write reactions of metals with dilute acids.
- ✔ I understand displacement reactions.
- ✔ I have memorised the reactivity series.
- ✔ I can explain formation of ionic compounds.
- ✔ I can explain properties of ionic compounds.
- ✔ I know minerals, ores and gangue.
- ✔ I can differentiate roasting and calcination.
- ✔ I know extraction methods based on the activity series.
- ✔ I can explain the thermit reaction.
- ✔ I can explain electrolytic refining.
- ✔ I know the rusting experiment.
- ✔ I know methods of preventing corrosion.
- ✔ I can define alloys and give common examples.
- ✔ I can explain important properties of non-metals.
- ✔ I have practised NCERT MCQs and case-based questions.
19. Exam Strategy for Metals and Non-metals
1. Memorise the Reactivity Series.
This is the key to solving displacement reactions, acid reactions and several extraction questions.
2. Learn the reaction patterns.
Revise: Metal + Oxygen, Metal + Water, Metal + Acid, Metal + Salt Solution.
3. Do not confuse Roasting and Calcination.
Roasting = sulphide ore + excess air.
Calcination = carbonate ore + limited air.
4. Practise Electrolytic Refining.
Remember: Impure metal = Anode, Pure metal = Cathode, and insoluble impurities form anode mud.
5. Revise corrosion examples.
Iron → rust, silver → black silver sulphide, copper → green basic copper carbonate.
🎯 High-Value Revision Chain:
Physical Properties → Chemical Properties → Oxygen → Water → Acids → Displacement → Reactivity Series → Ionic Compounds → Extraction → Refining → Corrosion → Alloys → Non-metals.
🎯 Ready for Your Class 10 Science Exam?
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