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Metals & Non-Metals — Homi Bhabha Class 9 Chemistry MCQs with Solutions
Free Homi Bhabha Class 9 Chemistry Metals & Non-Metals MCQs with step-by-step solutions covering Physical & Chemical Properties, Reactivity Series, Basics of Extraction, Corrosion & Prevention. Practise online on Prepizo — no login needed.
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Sample questions with solutions
Q1 — Physical & Chemical Properties · easy · theory
Which of the following is a general physical property of most metals?
A. They are brittle and do not conduct electricity
B. They always have very low melting points
C. They are malleable and good conductors of heat and electricity ✓ Correct
D. They are dull and exist as gases at room temperature
Solution: Most metals are malleable, ductile, sonorous, lustrous and good conductors of heat and electricity. Being brittle, dull and non-conducting are properties of typical non-metals.
Q2 — Physical & Chemical Properties · easy · theory
Non-metals are generally poor conductors of electricity. Which non-metal is an important exception because it does conduct electricity?
A. Sulphur
B. Iodine
C. Phosphorus
D. Graphite (a form of carbon) ✓ Correct
Solution: Graphite, an allotrope of carbon, conducts electricity because it has free (delocalised) electrons in its layered structure, even though carbon is a non-metal.
Q3 — Reactivity Series · easy · theory
In the reactivity series of metals, which of the following metals is the most reactive?
A. Gold
B. Iron
C. Copper
D. Potassium ✓ Correct
Solution: The reactivity series places the most reactive metals at the top. Potassium sits near the very top, while iron, copper and gold become progressively less reactive, with gold being one of the least reactive.
Q4 — Basics of Extraction · easy · theory
A naturally occurring solid from which a metal can be extracted profitably and conveniently is called
A. an ore ✓ Correct
B. a slag
C. an alloy
D. a gangue
Solution: An ore is a mineral from which a metal can be extracted profitably. Not every mineral is an ore, only those rich enough to make extraction worthwhile.
Q5 — Basics of Extraction · easy · theory
The unwanted earthy or rocky impurities present along with the metal compound in an ore are known as
A. gangue ✓ Correct
B. ore
C. slag
D. flux
Solution: The undesirable impurities such as sand and rocky matter present in an ore are called gangue. These are removed during the concentration and extraction steps.
Q6 — Corrosion & Prevention · easy · theory
The rusting of iron takes place only when iron is exposed to both
A. oxygen (air) and moisture (water) ✓ Correct
B. carbon dioxide and oil
C. sunlight and salt only
D. nitrogen and oil
Solution: Rusting is the slow corrosion of iron and needs both oxygen from the air and moisture (water). If either air or water is absent, iron does not rust, which is why iron kept in dry air or in boiled air-free water stays rust-free.
Q7 — Physical & Chemical Properties · hard · theory
The only metal that is liquid at room temperature is:
A. iron
B. copper
C. mercury ✓ Correct
D. sodium
Solution: Mercury is the only metal that is liquid at ordinary temperatures.
Q8 — Physical & Chemical Properties · hard · theory
Which non-metal is a good conductor of electricity (an exception)?
A. Phosphorus
B. Sulphur
C. Graphite ✓ Correct
D. Iodine
Solution: Graphite, a form of carbon, conducts electricity although it is a non-metal.
Q9 — Physical & Chemical Properties · hard · theory
The oxides of metals are generally ______, while the oxides of non-metals are generally ______:
A. neutral; acidic
B. basic; neutral
C. acidic; basic
D. basic; acidic ✓ Correct
Solution: Metal oxides are basic (e.g. Na₂O), whereas non-metal oxides are acidic (e.g. CO₂, SO₂).
Q10 — Physical & Chemical Properties · hard · theory
The hardest naturally occurring substance, which is a form of the non-metal carbon, is:
A. diamond ✓ Correct
B. graphite
C. iron
D. quartz
Solution: Diamond, an allotrope of carbon, is the hardest natural substance.
Q11 — Reactivity Series · hard · theory
When an iron nail is dipped in copper sulphate solution, the blue colour fades and the nail turns brownish because:
A. iron is more reactive and displaces copper ✓ Correct
B. no reaction occurs
C. copper is more reactive than iron
D. iron dissolves without reaction
Solution: Being more reactive, iron displaces copper from copper sulphate (Fe + CuSO₄ → FeSO₄ + Cu).
Q12 — Reactivity Series · hard · theory
Metals placed above hydrogen in the reactivity series can displace hydrogen from dilute acids. Which metal does NOT react with dilute hydrochloric acid?
A. Zinc
B. Magnesium
C. Copper ✓ Correct
D. Iron
Solution: Copper lies below hydrogen in the series, so it does not displace hydrogen from acids.
Q13 — Reactivity Series · hard · theory
A more reactive metal can displace a less reactive metal from its salt solution. Which pair will react?
A. Copper added to zinc sulphate solution
B. Silver added to copper sulphate solution
C. Zinc added to copper sulphate solution ✓ Correct
D. Gold added to iron sulphate solution
Solution: Zinc is more reactive than copper, so it displaces copper from copper sulphate.
Q14 — Basics of Extraction · hard · theory
Highly reactive metals like sodium and aluminium are extracted from their molten compounds by:
A. filtration
B. electrolysis ✓ Correct
C. simple hand-picking
D. heating with carbon
Solution: Very reactive metals cannot be reduced by carbon, so they are obtained by electrolytic reduction.
Q15 — Basics of Extraction · hard · theory
Metals of medium reactivity, such as iron and zinc, are usually extracted from their oxides by:
A. sublimation
B. evaporation
C. electrolysis only
D. reduction with carbon ✓ Correct
Solution: Their oxides are reduced by heating with carbon (a cheaper reducing agent) to give the metal.
Q16 — Basics of Extraction · hard · theory
Gold and silver are often found in nature in the free (native) state because they are:
A. very reactive
B. very unreactive (least reactive) ✓ Correct
C. non-metals
D. gases
Solution: Being at the bottom of the reactivity series, they do not readily combine with other elements and occur uncombined.
Q17 — Corrosion & Prevention · hard · theory
Rust is chemically:
A. iron chloride
B. pure iron
C. hydrated iron(III) oxide ✓ Correct
D. iron sulphide
Solution: Rust is hydrated iron(III) oxide, Fe₂O₃·xH₂O.
Q18 — Corrosion & Prevention · hard · theory
The green coating that forms on copper articles exposed to moist air is mainly:
A. copper chloride
B. iron oxide
C. basic copper carbonate ✓ Correct
D. copper sulphide
Solution: Copper corrodes to form a green layer of basic copper carbonate.
Q19 — Corrosion & Prevention · hard · theory
The black coating that dulls silver articles over time is due to the formation of:
A. silver oxide only
B. silver chloride
C. silver sulphide ✓ Correct
D. rust
Solution: Silver reacts with sulphur compounds in the air to form black silver sulphide (tarnish).
Q20 — Corrosion & Prevention · hard · theory
Iron objects rust faster near the sea because the moist air there contains:
A. no oxygen
B. no moisture
C. dissolved salts, which speed up corrosion ✓ Correct
D. only pure water
Solution: Salt-laden coastal air accelerates the electrochemical process of rusting.
Q21 — Physical & Chemical Properties · hard · theory
Assertion: Metals are described as electropositive elements. Reason: Metal atoms tend to lose their valence electrons to form positively charged ions. Choose the correct option.
A. Both assertion and reason are true, but the reason does not explain the assertion
B. Both assertion and reason are true, and the reason correctly explains the assertion ✓ Correct
C. The assertion is false but the reason is true
D. The assertion is true but the reason is false
Solution: Metals have few valence electrons which they lose easily to form positive ions (cations). This very tendency to lose electrons is why metals are called electropositive, so the reason correctly explains the assertion.
Q22 — Reactivity Series · hard · theory
Three metals P, Q and R are tested. P displaces Q from its salt solution, and Q displaces R from its salt solution, but R cannot displace P. Arrange the three metals in order of decreasing reactivity.
A. P > Q > R ✓ Correct
B. P > R > Q
C. Q > P > R
D. R > Q > P
Solution: A metal displaces a less reactive metal. Since P displaces Q, P is more reactive than Q; since Q displaces R, Q is more reactive than R. Therefore the order of decreasing reactivity is P > Q > R.
Q23 — Reactivity Series · hard · theory
Gold and silver are often found in nature in their free (uncombined) metallic state, whereas potassium and sodium are always found as compounds. The best explanation is that
A. gold and silver are very reactive and combine easily with other elements
B. all metals are found only as free elements
C. gold and silver are very unreactive, so they do not readily form compounds ✓ Correct
D. potassium and sodium are unreactive and stay uncombined
Solution: Very unreactive metals like gold and silver lie at the bottom of the reactivity series and do not readily react with air, water or other elements, so they occur free. Highly reactive metals such as sodium and potassium always occur combined as compounds.
Q24 — Basics of Extraction · hard · theory
Carbon is commonly used to reduce the oxides of moderately reactive metals such as zinc and iron, but it is NOT used to obtain aluminium from aluminium oxide. The reason is that
A. aluminium oxide does not contain any oxygen
B. carbon reacts violently with aluminium metal
C. aluminium is less reactive than carbon
D. aluminium is more reactive than carbon and holds its oxygen too strongly to be reduced by carbon ✓ Correct
Solution: A metal oxide can be reduced by carbon only if the metal is less reactive than carbon. Aluminium is more reactive than carbon, so carbon cannot pull oxygen away from aluminium oxide, and electrolysis is used instead.
Q25 — Basics of Extraction · hard · numerical
An ore contains 40 percent by mass of a metal. What mass of this ore must be processed to obtain 200 kg of the pure metal, assuming complete recovery?
A. 500 kg ✓ Correct
B. 80 kg
C. 200 kg
D. 400 kg
Solution: If 40 percent of the ore is metal, then metal mass = 0.40 times the ore mass. So the ore mass needed = 200 / 0.40 = 500 kg to obtain 200 kg of metal.
Q26 — Corrosion & Prevention · hard · theory
Aluminium is quite a reactive metal, yet aluminium articles do not corrode away and stay durable in everyday use. This is because
A. aluminium is actually one of the least reactive metals
B. aluminium never reacts with oxygen at all
C. a thin, tough layer of aluminium oxide forms on the surface and protects the metal underneath ✓ Correct
D. aluminium is always painted before it is used
Solution: Aluminium reacts quickly with oxygen to form a thin, hard, unreactive layer of aluminium oxide on its surface. This tightly stuck layer seals the metal beneath and stops further corrosion.
Q27 — Corrosion & Prevention · hard · theory
Large iron ships have blocks of magnesium or zinc bolted to their steel hulls below the waterline. The main purpose of these blocks is that they
A. are cheap decorations with no chemical role
B. being more reactive, corrode in place of the iron and so protect the hull ✓ Correct
C. make the ship float higher in the water
D. make the iron of the hull more reactive
Solution: Magnesium and zinc are more reactive than iron, so they corrode first and are eaten away instead of the hull. These sacrificial blocks are replaced from time to time and protect the iron ship from rusting.
Q28 — Physical & Chemical Properties · medium · theory
Metals can be beaten into thin sheets. This property is called:
A. malleability ✓ Correct
B. brittleness
C. sonority
D. ductility
Solution: Malleability is the ability to be hammered into sheets; ductility is being drawn into wires.
Q29 — Physical & Chemical Properties · medium · theory
Most metals are good conductors of:
A. sound only
B. heat and electricity ✓ Correct
C. neither heat nor electricity
D. only light
Solution: Metals conduct heat and electricity well due to free electrons.
Q30 — Physical & Chemical Properties · medium · theory
Non-metals in the solid state are generally:
A. malleable and shiny
B. good conductors
C. ductile
D. brittle and dull ✓ Correct
Solution: Solid non-metals are usually brittle, dull and poor conductors (with a few exceptions).