MATERIALS: METALS AND NON-METALS
1) What do you mean by malleability?
Answer: The property of metals by which they can be beaten into thin sheets is
called malleability. This is a characteristic property of metals.
2) What do you mean by ductility of a metal?
Answer: The property of metal by which it can be drawn into wires is called ductility.
3) What is sonorous metal?
Answer: Since metals produce ringing sounds, they are said to be sonorous.
4) Which materials are called metals? Give some examples of metals.
Answer: some materials are hard, lustrous, malleable, ductile, sonorous and good
conductors of heat and electricity. The materials which generally posses these
properties are called metals.
The examples of metals are iron, copper, aluminium, calcium, magnesium,
etc.
5) What are non metals? Give examples.
Answer: Materials like coal and sulphur are soft and dull in appearance. They break
down into powdery mass on tapping with hammer. They are not sonorous and are
poor conductors of heat and electricity. These materials are called non-metals.
The examples of non-metals are sulphur, carbon, oxygen, phosphorus, etc.
6) Name the only metal which is found in liquid state at room temperature?
Answer: Mercury is the only metal which is found in liquid state at room
temperature.
7) What happens when a copper vessel is exposed to moist air for long?
Answer: When a copper vessel is exposed to moist air for long, it acquires a dull
green coating. The green material is a mixture of copper hydroxide (Cu (OH)2) and
copper carbonate (CuCO3). The following is the reaction
8) In general, metallic oxides are basic in nature. True or false.
Answer: True.
9) Non-metals react with water. True or False?
Answer: False.
10) Why non-metals are stored in water? Give one example.
Answer: Non-metals do not react with water though they may be very reactive in air.
That is why such non-metals are stored in water.
Phosphorus is a very reactive non-metal. It catches fire if exposed to air. To
prevent the contact of phosphorus with atmospheric oxygen, it is stored in water.
11) Non metals generally do not react with acids but metals react with acids and produce
hydrogen gas that burns with a ‘pop’ sound. True or false.
Answer: True.
12) What is the product formed when metals react with acids?
Answer: when metals react with acids hydrogen gas is formed.
13) Copper reacts with dilute hydrochloric acid even on heating but it does not react with
sulphuric acid. True or false.
Answer: False.
14) Metals react with acids and burn with a ‘pop’ sound. What does the ‘pop’ sound
indicate?
Answer: The ‘pop’ sound indicates the presence of hydrogen gas.
15) Metals react with sodium hydroxide to produce hydrogen gas. True or false.
Answer: True.
16) What is displacement reaction?
Answer: The reaction in which one metal displaces another metal from its compound
in aqueous solution is called displacement reaction.
17) How will you explain the following reaction
Copper Sulphate (CuSO4) + Zinc (Zn)
(Blue)
→ Zinc Sulphate (ZnSO4) + Copper (Cu)
(Colourless)
(Red)
Answer: In the reaction, zinc (Zn) replaces copper (Cu) from copper sulphate
(CuSO4). That is why the blue colour of copper sulphate disappears and a powdery
red mass of copper is deposited at the bottom of the beaker.
18) When Zinc sulphate (ZnSO4) reacts with Copper turnings (Cu), copper is not able to
replace zinc from zinc sulphate. Why?
Answer: Zinc is more reactive than copper and iron. A more reactive metal can
replace a less reactive metal, but a less reactive one cannot replace a more reactive
metal. That is why, copper is not able to replace zinc from zinc sulphate when Zinc
sulphate (ZnSO4) reacts with Copper turnings (Cu).
19) What are the main applications of metals?
Answer: Metals are used in making machinery, automobiles, aeroplanes, trains,
satellites, industrial gadgets, cooking utensils, water boilers, etc.
20) What are the main applications of non metals?
Answer: The main applications of non metals are
 Non-metal essential for our life which all living beings inhale during
breathing,
 Non-metals used in fertilisers to enhance the growth of plants,
 Non-metal used in water purification process,
 Non-metal used in the purple coloured solution which is applied on wounds
as an antiseptic
 Non-metals used in crackers.
21) Which of the following can be beaten into thin sheets?
(a) Zinc (b) Phosphorus (c) Sulphur (d) Oxygen
Answer: (a) Zinc As Zinc is a metal and metal has property of malleability (Can be
converted in sheet by beating). Rest of these are non-metals.
22) Which of the following statements is correct?
(a) All metals are ductile.
(b) All non-metals are ductile.
(c) Generally, metals are ductile.
(d) Some non-metals are ductile.
Answer: (c) Generally, metals are ductile. Mercury (metal) is liquid at room
temperature and cannot be drawn into wires. Therefore, it is non-ductile. So the
option (a) is incorrect. Not a single non-metal is ductile, so option (b) and (d) are
incorrect.
23) Fill in the blanks:
(a) Phosphorus is very ___________ non-metal.
(b) Metals are ___________ conductors of heat and ___________.
(c) Iron is ___________ reactive than copper.
(d) Metals react with acids to produce ___________ gas.
Answer: (a) Phosphorus is very reactive non-metal.
(b) Metals are good conductors of heat and electricity.
(c) Iron is more reactive than copper.
(d) Metals react with acids to produce Hydrogen gas.
24) Give reasons for the following:
(a) Aluminium foils are used to wrap food items.
(b) Immersion rods for heating liquids are made up of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
(d) Sodium and potassium are stored in kerosene.
Answer:
(a) Aluminium foils are used to wrap food items because aluminium is highly
malleable. It can be beaten into thin sheets. Moreover, it does not react with food.
(b) Metals are good conductors of heat and electricity. Therefore, immersion rods
for heating liquids are made of metallic substances.
(c) The reactivity of zinc is higher than copper. Only a metal of higher reactivity can
displace a metal of lower reactivity from its salt solution. So, copper cannot displace
zinc from zinc sulphate solution.
(d) Sodium and potassium are highly reactive metals. They can catch fire even when
they come in contact with air. So, they have to be kept in kerosene.
25) Can you store lemon pickle in an aluminium utensil? Explain.
Answer: No, we cannot store lemon pickle in aluminium utensils, as metals react
with acids to liberate hydrogen gas. The pickle (which is acidic in nature) can be
spoiled.
26) In the following Table some substances are given in Column I. In Column II some uses
are given. Match the items in column I with those in Column II.
Answer:
27) What happens when
(a) Dilute sulphuric acid is poured on a copper plate?
(b) Iron nails are placed in copper sulphate solution? Write word equations of the
reactions involved.
Answer: (a) Copper does not react with dilute sulphuric acid. When concentrated
sulphuric acid is poured on a copper plate, copper reacts with sulphuric acid to liberate
hydrogen gas.
(b) The reactivity of iron is more than copper. So, iron will displace copper from copper
sulphate solution. In this reaction, the blue colour of copper sulphate fades.
28) Saloni took a piece of burning charcoal and collected the gas evolved in a test tube.
(a) How will she find the nature of the gas?
(b) Write down word equations of all the reactions taking place in this process.
Answer:
(a) Some water is added in the test tube in which gas is collected. Now, cover the test
tube. Shake it well. The solution is then tested with blue litmus and red litmus. Blue
litmus turns red. Thus, the nature of gas is acidic.
(b) Charcoal when reacts with oxygen forms carbon dioxide gas