Question 1

The only metal that is liquid at room temperature is:

Accepted Answer

mercury. Mercury is the only metal that is liquid at ordinary temperatures.

Question 2

Which non-metal is a good conductor of electricity (an exception)?

Accepted Answer

Graphite. Graphite, a form of carbon, conducts electricity although it is a non-metal.

Question 3

The oxides of metals are generally ______, while the oxides of non-metals are generally ______:

Accepted Answer

basic; acidic. Metal oxides are basic (e.g. Na₂O), whereas non-metal oxides are acidic (e.g. CO₂, SO₂).

Question 4

The hardest naturally occurring substance, which is a form of the non-metal carbon, is:

Accepted Answer

diamond. Diamond, an allotrope of carbon, is the hardest natural substance.

Question 5

When an iron nail is dipped in copper sulphate solution, the blue colour fades and the nail turns brownish because:

Accepted Answer

iron is more reactive and displaces copper. Being more reactive, iron displaces copper from copper sulphate (Fe + CuSO₄ → FeSO₄ + Cu).

Question 6

Metals placed above hydrogen in the reactivity series can displace hydrogen from dilute acids. Which metal does NOT react with dilute hydrochloric acid?

Accepted Answer

Copper. Copper lies below hydrogen in the series, so it does not displace hydrogen from acids.

Question 7

A more reactive metal can displace a less reactive metal from its salt solution. Which pair will react?

Accepted Answer

Zinc added to copper sulphate solution. Zinc is more reactive than copper, so it displaces copper from copper sulphate.

Question 8

Highly reactive metals like sodium and aluminium are extracted from their molten compounds by:

Accepted Answer

electrolysis. Very reactive metals cannot be reduced by carbon, so they are obtained by electrolytic reduction.

Question 9

Metals of medium reactivity, such as iron and zinc, are usually extracted from their oxides by:

Accepted Answer

reduction with carbon. Their oxides are reduced by heating with carbon (a cheaper reducing agent) to give the metal.

Question 10

Gold and silver are often found in nature in the free (native) state because they are:

Accepted Answer

very unreactive (least reactive). Being at the bottom of the reactivity series, they do not readily combine with other elements and occur uncombined.

Question 11

Rust is chemically:

Accepted Answer

hydrated iron(III) oxide. Rust is hydrated iron(III) oxide, Fe₂O₃·xH₂O.

Question 12

The green coating that forms on copper articles exposed to moist air is mainly:

Accepted Answer

basic copper carbonate. Copper corrodes to form a green layer of basic copper carbonate.

Question 13

The black coating that dulls silver articles over time is due to the formation of:

Accepted Answer

silver sulphide. Silver reacts with sulphur compounds in the air to form black silver sulphide (tarnish).

Question 14

Iron objects rust faster near the sea because the moist air there contains:

Accepted Answer

dissolved salts, which speed up corrosion. Salt-laden coastal air accelerates the electrochemical process of rusting.

Question 15

Metals can be beaten into thin sheets. This property is called:

Accepted Answer

malleability. Malleability is the ability to be hammered into sheets; ductility is being drawn into wires.

Question 16

Most metals are good conductors of:

Accepted Answer

heat and electricity. Metals conduct heat and electricity well due to free electrons.

Question 17

Non-metals in the solid state are generally:

Accepted Answer

brittle and dull. Solid non-metals are usually brittle, dull and poor conductors (with a few exceptions).

Question 18

Metals produce a ringing sound when struck. This property is called:

Accepted Answer

sonority. Sonority is the property of producing a ringing sound; that is why metals are used in bells.

Question 19

In the reactivity series of metals, the most reactive metal among the following is:

Accepted Answer

potassium. Potassium is near the top of the reactivity series and is the most reactive of these.

Question 20

The least reactive metal among the following is:

Accepted Answer

gold. Gold is at the bottom of the reactivity series and is the least reactive.

Metals & Non-Metals — Homi Bhabha Exam Chemistry MCQs with Solutions

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Sample questions with solutions