SMART EDUCATIONS 1
Metals and Non-metals
Q. What is metal?
Ans. The element which has the ability to lose electrons is known as metal.
OR
The element is known as metal which has the following physical
properties:-
Solid state, malleability, ductility, sonorosity, conductor of heat and
electricity, metallic luster, high melting and boiling point.
Example of metals:- Sodium, Magnesium, Iron, Gold, Silver etc.
Q. What is malleability?
Ans. The ability of metal by which it can be converted into thin sheets by
beating, is called malleability. Gold and silver are the most malleable
metals.
But some metals are non malleable(brittle). For example:- Zinc,
mercury and some other metals also.
Q. What is ductility?
Ans. The ability of metals to be drawn into thin wires is called ductility. Gold
is the most ductile metal. A wire of about 2 km length can be drawn from
one gram of gold.
But some metals are non ductile. For example:- Zinc, mercury,
sodium, potassium and some other metals also.
Q. What is sonorosity?
Ans. When metal is striked by a hard object, it produces a ringing sound.
This property is called sonorosity. Silver is the most sonorous metal.
But some metals are non sonorous. For example:- Lead, mercury,
sodium, potassium and some other metals also.
Q. What does metallic lustre mean?
Ans. Metals, in their pure state, have a shining surface. This property is
called metallic lustre. Silver is the most sonorous metal.
SMART EDUCATIONS 2
Q. Why are metals a good conductor of electricity?
Ans. Metals are good conductors of electricity because they have free
electrons which carry the charge through them and make them a good
conductor of electricity. Silver is the best conductor of electricity.
But lead is a poor conductor of electricity.
Q. What are exceptional found in metals related to physical properties?
Ans.
1. Mercury is the only metal, which is found in liquid state.
2. Zinc and mercury are not ductile metals.
3. Zinc, mercury, sodium and potassium are not ductile.
4. Lead, mercury, sodium and potassium are not sonorous.
5. Lead and mercury are comparatively poor conductors of heat.
6. Lead is a poor conductor of electricity.
7. Mercury, gallium, caesium and sodium have comparatively low
melting points.
8. Alkali metals like:- lithium, sodium, potassium are so soft that they
can be cut with a knife. They have low densities and low melting
points.
Q. Q. What is nonmetal?
Ans. The element which has the ability to gain electrons is known as
nonmetal.
OR
The element is known as nonmetal which does not have the following
physical properties:-
Solid state, malleability, ductility, sonorosity, conductor of heat and
electricity, metallic luster, high melting and boiling point.
Example of nonmetals:- Oxygen, Hydrogen, Iodine, Chlorine, Carbon,
etc.
Q. What are exceptional found in nonmetals related to physical properties?
Ans.
1. Bromine is the only nonmetal, which is found in liquid state.
2. Graphite is a good conductor of electricity.
SMART EDUCATIONS 3
3. Iodine has lustre.
4. Graphite is the hardest natural substance known and has a very high
melting and boiling point.
Q. Give an example of a metal which
(i) is a liquid at room temperature.
Ans. Mercury.
(ii) can be easily cut with a knife.
Ans. Sodium.
(iii) is the best conductor of heat.
Ans. Silver.
(iv) is a poor conductor of heat.
Ans. Lead
Q. What are the chemical properties of metals?
Ans. The chemical properties of metals are:-
1. Metals react with oxygen and form metal oxide, which is basic in
nature.
Metal + Oxygen Metal Oxide(Base)
Ex:- 2Cu + O
2
2CUO
Exceptions:-
● Metals like Aluminium and zinc react with O
2
to form base as
well as acid. Such metals are called amphoteric oxides.
● Some metals like Iron and copper are to be heated to react with
O
2
● Silver and gold do not react with oxygen even at high
temperatures.
2. Metals react with water to form metal oxide / metal hydroxide and
hydrogen gas.
Metal + water Metal oxide / Metal hydroxide + Hydrogen
gas
Ex:- 2K + 2H
2
O → 2KOH + H
2
+ heat energy
Exceptions:-
● Some metals that react with even cold water are :- Na, K, Li,
Ca.
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● Some metals that react with only hot water are :- Mg.
● Some metals that react with only steam are :- Al, Zn, Fe and
they do not form metal hydroxide but metal oxide.
● Some metals do not react with water at all and they are:- Pb,
Cu, Ag and Au
●
3. Metals react with acid to form salt and hydrogen gas.
Metal + Acid Salt + H
2
Ex:- Mg + 2HCl MgCl
2
+ H
2
Exceptions:-
● Hydrogen gas is not evolved when a metal reacts with nitric
acid. They react to form salt and water. But when the metals are
Mg and Mn then they can form salt and hydrogen gas.
● The metals which are less reactive than hydrogen, do not react
with acid at all.
4. Higher reactive metals react with lower reactive metals salt then the
displacement reaction occurs.
Metal A + Salt solution of B Salt solution of A + Metal B
Ex:- 2Na + MgCl
2
2NaCl + Mg
5. Metals react with nonmetals to form ionic compounds by transferring
of their electrons.
Q. What is amphoteric oxide?
Ans. The metal oxide which is basic as well as acidic in nature, is called
amphoteric oxide. Al
2
O
3
and ZnO are the examples of amphoteric oxides.
Q. What is alkali?
Ans. The bases which are soluble in water are called alkali. Examples of
alkali are :- NaOH, Mg(OH)
2
, KOH, Ca(OH)
2
.
All alkalis are base but not all bases are alkalis.
SMART EDUCATIONS 5
Q. What is anodising?
Ans. Anodising is a process of forming a thick oxide layer over a metal
which prevents the metals from further oxidising. The process is called
anodising because in this process a pure metal is formed anode and is
electrolysed with dilute sulphuric acid. The oxygen gas evolved at the
anode reacts with aluminium to make a thicker protective oxide layer. Iron
metal cannot be anodised.
Q. Why do Calcium and Magnesium float on water even though they have
higher density than water?
Ans. Calcium and Magnesium react with cold water and hot water
respectively and evolve hydrogen gas which sticks to their surfaces and
make them float on water.
Q. Why does metal(other than Mg and Mn) not evolve hydrogen gas, when
it reacts with Nitric acid?
Ans. Nitric acid is a strong oxidising agent. It oxidises the H
2
produced to
water and itself gets reduced to any of the nitrogen oxides (N
2
O, NO, NO
2
).
For example:-
Fe + 4HNO
3
Fe(NO
3
)
3
+ NO + 2H
2
O
Q. What is aqua regia (royal water)?
Ans. Aqua regia, (Latin for ‘royal water’) is a freshly prepared mixture of
concentrated hydrochloric acid and concentrated nitric acid in the ratio of
3:1. It can dissolve gold and platinum, even though neither of these acids
can do so alone.
Q. What is the reactivity series?
Ans. The reactivity series is a list of metals arranged in the order of their
decreasing activities which is as follows:-
SMART EDUCATIONS 6
Q. Why is sodium kept immersed in kerosene oil?
Ans. Sodium is a highly reactive metal. It reacts with water and oxygen so
vigorously that they catch fire if kept in the open or in water. Hence, to
protect them and to prevent accidental fires, they are kept immersed in
kerosene oil.
Q. Write equations for the reactions of
(i) iron with steam
Ans. Fe(s) + H
2
O(g) → Fe
3
O
4
(s) + H
2
(g)
(ii) Calcium and Potassium with water
Ans. Ca + H
2
O → Ca(OH)
2
+ H
2
K + H
2
O → KOH + H
2
+ Heat energy.
Q. 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.
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Use the Table above to answer the following questions about metals
A, B, C and D.
(i) Which is the most reactive metal?
Ans. Metal B
(ii) What would you observe if B is added to a solution of Copper(II)
sulphate?
Ans. Metal B will displace the copper from the Copper(II)
Sulphate.
(iii) Arrange the metals A, B, C and D in the order of decreasing reactivity.
Ans. B < A < C < D
Q. Which gas is produced when dilute hydrochloric acid is added to a
reactive metal? Write the chemical reaction when iron reacts with dilute
H
2
SO
4
.
Ans. Hydrogen gas is produced when dilute hydrochloric acid is added to a
reactive metal. The chemical reaction is as follows:-
Fe + H
2
SO
4
→ FeSO
4
+ H
2
Q. What would you observe when zinc is added to a solution of iron(II)
sulphate? Write the chemical reaction that takes place.
Ans. When zinc is added to a solution of iron(II) sulphate, a grey precipitate
of iron is formed leaving behind a colourless solution of Zinc sulphate.
The chemical reaction that takes place in this case is as follows:-
Zn + FeSO
4
→ Fe + ZnSO
4
Q. What is an ionic compound or electrovalent compound?
Ans. The compound formed by the transfer of electrons from metals to
nonmetals is called an ionic compound or electrovalent compound.
Formation of ionic compound is as follows:-
SMART EDUCATIONS 8
Metal loses electrons to form cation(+ve charge) and nonmetal
gain electrons to form anion(-ve charge) and thus the two opposite charges
attract each other to form an ionic compound.
Q. What are the properties of an ionic compound?
Ans. Following are the properties of an ionic compound:-
● Ionic compounds are solid and brittle.
● Ionic compounds have high melting and boiling point.
● Ionic compounds are generally soluble in water and insoluble in
solvents such as kerosene, petrol, etc.
● Ionic compounds in the solid state do not conduct electricity but they
conduct electricity in the molten state or in aqueous solution.
Q. Write the electron-dot structure for sodium, oxygen and magnesium.
Ans.
Q. Show the formation of Na
2
O and MgO by the transfer of electrons and
what are the ions present in them?
Ans. Formation of Na
2
O :-
Na → Na
+
+ e
-
(2,8,1) (2,8)
O + 2e
-
→ O
2-
(2,6) (2,8)
SMART EDUCATIONS 9
Ions in Na
2
O are Na has +ve ions(cation) and O has -ions(anion)
Formation of MgO:-
Mg → Mg
2+
+ 2e
-
(2,8,2) (2,8)
O + 2e
-
→ O
2-
(2,6) (2,8)
Ions in MgO are Mg has +ve ions(cation) and O has -ions(anion)
Q. Why do ionic compounds have high melting points?
Ans. Ionic compounds are formed by the strong force of attraction between
the two opposite ions, so a considerable amount of energy is required to
break the strong inter-ionic attraction and to melt them. So they have high
melting points.
Q. Where do metals occur?
Ans. The earth’s crust is the major source of metals. Seawater also
contains some soluble salts such as sodium chloride, magnesium chloride,
etc.
Q. What do minerals mean?
Ans. The elements or compounds, which occur naturally in the earth’s
crust, are known as minerals.
Q. What do ores mean?
Ans. The minerals, which contain a very high percentage of a particular
metal and the metal can be profitably extracted from it. These minerals are
called ores.
SMART EDUCATIONS 10
Q. What does extraction of metals mean?
Ans. The conversion of ores into pure metals is called extraction of metals.
Several steps are involved in the extraction of pure metal from ores.
Q. Which metals are found in free state?
Ans. The metals at the bottom of the activity series are the least reactive.
They are often found in a free state. For example, gold, silver, platinum and
copper are found in the free state. Copper and silver are also found in the
combined state as their sulphide or oxide ores.
Q. Why are most ores of metals found in their oxides form?
Ans. The ores of many metals are oxides because oxygen is a very
reactive element and is very abundant on the earth.
Q. What does gangue mean?
SMART EDUCATIONS 11
Ans. Ores mined from the earth are usually contaminated with large
amounts of impurities such as soil, sand, etc., called gangue.
Q. What are the processes of extracting the metals which are least
reactive?
Ans. Metals low in the activity series are very unreactive. The oxides of
these metals can be reduced to metals by heating alone. For example,
cinnabar (HgS) is an ore of mercury. When it is heated in air, it is first
converted into mercuric oxide (HgO). Mercuric oxide is then reduced to
mercury on further heating.
2HgS(s) + 3O
2
(g)
Heat
2HgO(s) + 2SO
2
(g)
2HgO(s)
Heat
2Hg(l) + O
2
(g)
Similarly, copper which is found as Cu 2 S in nature can be obtained
from its ore by just heating in air.
2Cu
2
S(s) + 3O
2
(g)
Heat
2Cu
2
O(s) + 2SO
2
(g)
2Cu
2
O(s)+Cu
2
S(s))
Heat
6Cu(s) + SO
2
(g)
Q. Why are all the ores of metals converted first into metal oxide?
Ans. It is easier to obtain a metal from its oxide, as compared to its
sulphides and carbonates. Therefore the metal sulphides and carbonates
must be converted into metal oxides first.
The metal oxides are then reduced to the corresponding metals by
using suitable reducing agents such as carbon. For example, when zinc
oxide is heated with carbon, it is reduced to metallic zinc.
ZnO(s) + C(s) → Zn(s) + CO(g)
Besides using carbon (coke) to reduce metal oxides to metals,
sometimes displacement reactions can also be used.
Q. What is roasting?
Ans. The sulphide ores are converted into oxides by heating strongly in the
presence of excess air. This process is known as roasting.
SMART EDUCATIONS 12
For example:-
2ZnS + 3O
2
Heat
2ZnO + 2SO
2
Q. What is calcination?
Ans. The carbonate ores are changed into oxides by heating strongly in
limited air. This process is known as calcination.
ZnCO
3
Heat
ZnO + CO
2
Q. What is the thermite reaction?
Ans. The reaction of iron(III) oxide (Fe
2
O
3
) with aluminium is used to join
railway tracks or cracked machine parts. This reaction is known as the
thermite reaction.
Fe
2
O
3
(s) + 2Al(s) → 2Fe(l) + Al
2
O
3
(s) + Heat
3MnO
2
(s) + 4Al(s) → 3Mn(l) + 2Al
2
O
3
(s) + Heat
The amount of heat evolved in this reaction is so large that the metal is
produced in the molten state.
Q. Why is the use of carbon for reduction process effectless in the case of
high reactive metals?
Ans. The metals high up in the reactivity series are very reactive. They
cannot be obtained from their compounds by heating with carbon. This is
because these metals have more affinity for oxygen than carbon. These
metals are obtained by electrolytic reduction.
Q. What is electrolytic reduction?
Ans. Electrolytic reduction is a process through which highly reactive metal
is obtained from their molten chlorides. In this process the metal
chloride/oxide is used as electrolysis and graphites are used as electrodes.
When electricity is passed through the electrolyte, the pure metal is
deposited at the cathode and chlorine is liberated at the anode. The
reactions are –
At cathode Na
+
+ e
–
→ Na
At anode 2Cl
–
→ Cl
2
+ 2e
–
For example, sodium, magnesium, aluminium and calcium are
obtained by electrolytic reduction.
SMART EDUCATIONS 13
Q. What is electrolytic refining?
Ans. After the process of reduction(whether it be simple reduction or
electrolytic reduction) the obtained metals 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. Many metals,
such as copper, zinc, tin, nickel, silver, gold, etc., are refined electrolytically.
In this process, 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
an electrolyte. On passing the current through the electrolyte, the pure
metal from the anode dissolves into the electrolyte. An equivalent amount
of pure metal from the electrolyte is deposited on the cathode. The soluble
impurities go into the solution, whereas, the insoluble impurities settle down
at the bottom of the anode and are known as anode mud.
Q. What is anode mud?
Ans. The insoluble impurities settle down during the process of electrolytic
refining, at the bottom of the anode and are known as anode mud.
Q. Name two metals which are found in nature in the free state.
Ans. Gold and Platinum.
Q. What chemical process is used for obtaining a metal from its oxide?
Ans. Reduction process is used for obtaining a metal from its oxide with
the help of reducing agents like carbon or highly reactive metals.
Q. What is corrosion?
Ans. Corrosion is a chemical process in which a pure metal loses its shine
after reacting atmospheric air. For example:-
● Silver articles become black because they react with sulphur in the air
to form a coating of silver sulphide.
● Copper articles become green because they react with carbon
dioxide in the air to form a coating of copper carbonate.
● Iron articles become reddish brown because it reacts with oxygen
and water in the air to form a coating of rust.
SMART EDUCATIONS 14
Q. What are the conditions required to rust an iron?
Ans. Presence of oxygen, water and an iron article are the conditions
required to rust an iron.
Q. What are the preventions of corrosion?
Ans. The rusting of iron can be prevented by painting, oiling, greasing,
galvanising, chrome plating, anodising or making alloys.
Q. What is galvanisation?
Ans. Galvanisation is a method of protecting steel and iron from rusting
by coating them with a thin layer of zinc.
Q. What is alloying?
Ans. Mixing a metal with other metals or nonmetals is alloying. Alloy is a
homogeneous mixture. 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.
Q. What are the examples of alloy and their constituents?
Ans.
Alloy
Constituents
Amalgam
Mercury and any metal
Brass
Copper and Zinc
Bronze
Copper and Tin
Solder
Lead and Tin
Steel
Iron and Carbon
Stainless Steel
Iron, Carbon, Nickel, Chromium,
Silicon and Manganese.
SMART EDUCATIONS 15
Q. Metallic oxides of zinc, magnesium and copper were heated with the
following metals.
In which cases will you find displacement reactions taking place?
Ans.
Q. Which metals do not corrode easily?
Ans. Gold and Platinum.
Q. What are alloys?
Ans. Alloy is a homogeneous mixture of a metal with metals or with
nonmetals.
EXERCISES
Q. Which of the following pairs will give displacement reactions?
Ans. AgNO
3
solution and copper metal.
Q. Which of the following methods is suitable for preventing an iron frying
pan from rusting?
Ans. Applying a coating of zinc.
Q. An element reacts with oxygen to give a compound with a high melting
point. This compound is also soluble in water. The element is likely to be
Ans. Calcium.
SMART EDUCATIONS 16
Q. Food cans are coated with tin and not with zinc because
Ans. Zinc is more reactive than tin.
Q. You are given a hammer, a battery, a bulb, wires and a switch.
(a) How could you use them to distinguish between samples of metals and
non-metals?
Ans. With the hammer we will beat the sample and if it can be beaten into
thin sheets then it is a metal otherwise a non-metal. Similarly we will use
the battery bulb wires and a switch to set up a circuit with the sample and if
the bulb glows then it is a metal otherwise a non-metal.
Q. You are given a hammer, a battery, a bulb, wires and a switch.
(b) Assess the usefulness of these tests in distinguishing between metals
and nonmetals.
Ans. Because of the malleability of metals, we can cast them into sheets,
which can be used for various purposes . For example, iron sheets are
used for roofing and for making trunks, boxes etc.
Metals are good conductors of electricity. It is because of this
property that metal wires made up of copper and aluminium are used for
carrying electricity.
Q. What are amphoteric oxides? Give two examples of amphoteric oxides.
Ans. The metal oxide which is basic as well as acidic in nature, is called
amphoteric oxide. Al
2
O
3
and ZnO are the examples of amphoteric oxides.
Q. Name two metals which will displace hydrogen from dilute acids, and
two metals which will not.
Ans. The two metals which will displace hydrogen from dilute acids are:-
Calcium and Magnesium.
The two metals which will not displace hydrogen from dilute acids
are:- Copper and silver.
Q. In the electrolytic refining of a metal M, what would you take as the
anode, the cathode and the electrolyte?
Ans. In the electrolytic refining of a metal M, we would take
SMART EDUCATIONS 17
Anode:- Impure metal of M
Cathode:- Pure metal of M
Electrolyte:- Water soluble salt of M
Q. Pratyush took sulphur powder on a spatula and heated it. He collected
the gas evolved by inverting a test tube over it, as shown in figure below.
(a) What will be the action of gas on (i) dry litmus paper? (ii) moist litmus
paper?
(b) Write a balanced chemical equation for the reaction taking place.
Ans(a) When sulphur is heated in air it produce sulphur dioxide(SO
2
)
(i). The gas is acidic in nature but in the absence of water it will not show
the acidic nature, So, there will be no action of the gas on dry litmus paper.
(ii). Moist blue litmus will be converted into red litmus by the gas.
Ans(b) A balanced chemical equation for the reaction are:-
S(s) + O
2
(g) → SO
2
(g)
SO
2
(g) + H
2
O(aq) → H
2
SO
3
(aq)
Q. State two ways to prevent the rusting of iron.
Ans. Painting or Galvanizing.
Q. What type of oxides are formed when nonmetals combine with oxygen?
Ans. Nonmetals combine with oxygen to form two types of oxide:-
1. Acidic oxide like SO
2
, NO
2
etc.
2. Neutral oxide like H
2
O, CO etc.
Q. Give reasons
(a) Platinum, gold and silver are used to make jewellery.
Ans. Because they are so malleable and ductile to convert into any shapes
and are nonreactive and do not corrode so their shine remains for a long
time.
(b) Sodium, potassium and lithium are stored under oil.
Ans. Sodium, potassium and lithium are highly reactive metals. They react
with water and oxygen so vigorously that they catch fire if kept in the open
or in water. Hence, to protect them and to prevent accidental fires, they are
kept immersed in kerosene oil.
SMART EDUCATIONS 18
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for
cooking.
Ans. Because it is a good conductor of heat and it can be anodised to
prevent it from reacting with food.
(d) Carbonate and sulphide ores are usually converted into oxides during
the process of extraction.
Ans. Because It is easier to obtain a metal from its oxide, as compared to
its sulphides and carbonates.
Q. You must have seen tarnished copper vessels being cleaned with lemon
or tamarind juice. Explain why these sour substances are effective in
cleaning the vessels.
Ans. Tarnished copper vessels means the copper forms a thin layer of
copper carbonate, which is basic and lemon or tamarind juice contain acid.
So the acid and the base neutralise each other and the shine of the copper
is restored.
Q. Differentiate between metal and non-metal on the basis of their chemical
properties.
Ans.
Metal
Nonmetal
It contains cations.
It contains anions.
It reacts with O
2
to form a basic
oxide.
It reacts with O
2
to form an acidic
oxide or neutral.
Very few metals react with
hydrogen to form ionic hydride.
It combines with hydrogen to form
covalent hydride.
It reacts with acid to form salt and
H
2
It does not react with acid
It reacts with water to form metal
It does not react with water.
SMART EDUCATIONS 19
oxide or metal hydroxide.
Q. A man went door to door posing as a goldsmith. He promised to bring
back the glitter of old and dull gold ornaments. An unsuspecting lady gave
a set of gold bangles to him which he dipped in a particular solution. The
bangles sparkled like new but their weight was reduced drastically. The
lady was upset but after a futile argument the man beat a hasty retreat.
Can you play the detective to find out the nature of the solution he had
used?
Ans. The man used aqua-regia, a mixture of nitric acid and hydrochloric in
the ratio of 1:3. On dipping a gold in it, it dissolves the outer layer of the
gold and the shiny inner layer appears. Because the outer layer was
dissolved in the aqua-regia so the weight of the gold was reduced.
Q. Give reasons why copper is used to make hot water tanks and not steel
(an alloy of iron).
Ans. Because copper does not react with water at any cost but iron reacts
with steam, so copper is used to make hot water tanks and not steel (an
alloy of iron).
