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Published on: 30/07/2018
In this question paper prepared from the chapter Metals and Non-metals.The important questions are covers from the Higher Order Thinking Questions and Value Based Questions.
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Questions + Answers key
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1.
Which of the following is very hard?
Copper
Sodium
Potassium
Coal
2.
Which metal is present in haemoglobin?
Magnesium
Iron
Carbon
Zinc
3.
Which of the following non-metals reacts and catches fire on exposure to air?
Phosphorus
Nitrogen
Sulphur
Hydrogen
4.
Which of the following reacts with cold water vigorously?
Carbon
Sodium
Magnesium
Sulphur
5.
Which of the following statements is correct?
All metals are ductile
All non-metals are ductile
Generally, metals are ductile
Some non-metals are ductile
6.
The oxides of metals are...........in nature
7.
Copper is.................reactive than zinc.
8.
..................litmus paper turns...............when it is dipped in a basic solution.
9.
Materials can be classified into.....and....
10.
Metals are ______________ conductors of heat and __________________.
11.
Iron is used in constructing bridges and houses
12.
Some metals react with sodium hydroxide to produce hydrogen gas.
13.
Oxides of non-metals and metals are acidic in nature.
14.
Coal can be drawn into wires.
15.
Generally, non-metals react with acids.
16.
Shikha bought a new iron container and kept blue copper sulphate solution in it. Next day, she found that blue colour of copper sulphate solution fades and iron container becomes porous. She went to the shopkeeper and complaint that iron container is not of good quality. But the shopkeeper argued that container is of good quality and he is not giving her money back, By chance, her friend Mohan came there and asked the matter, and told that the container is of good quality and you have kept the wrong substances in it, so fault is all yours.
On the basis of the above passage answer the following questions.
(a) Why the container becomes porous when blue copper sulphate solution is kept in it?
(b) What qualities are exhibited by Mohan.
17.
In what form magnesium is found in plants?
18.
If a blacksmith beats an iron piece with hammer. Do you think, will it Change its shape? If yes, would you expect a similar Change in woodlog on beating?
19.
We should not store food stuff in container which is made up of metals such as copper, zinc, aluminium, etc. Why?
20.
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.
21.
Which metal reacts neither with cold water nor with hot water?
22.
Some non-metals like phosphorus are kept in water to protect them from atmospheric oxygen. Write the property of non-metals utilised here.
23.
Name the metal
(a) which reacts with dilute hydrochloric acid to produce hydrogen gas.
(b) which does not react with dilute hydrochloric acid.
24.
Write physical properties of metals.
25.
Name the property which enables metals to be drawn into wires.
26.
Metals are malleable and ductile. They possess such properties which make them useful for a number of purposes, e.g. in making coins, jewellery, electrical wires, etc. For different requirements, different metals are used. It depends on the nature of metals. Now give the answer of the following questions.
(a) Give two reasons why gold is used in making jewellery?
(b) If you have to select the metal among copper, aluminium and silver for the transmission of electricity, which one would you prefer and why?
(c) Between silver and copper, which is the better conductor of heat?
(d) Generally, silver foils are used for the decoration of sweets. Are they harmful for us? If yes, then in what manner?
27.
Iron is more reactive than copper. Can you write an activity to show this?
1.
(b)
Sodium
2.
(d)
Zinc
3.
(a)
Phosphorus
4.
(b)
Sodium
5.
(c)
Generally, metals are ductile
6.
( )
basic
7.
( )
less
8.
( )
Red,blue
9.
( )
metals,non-metals
10.
( )
good, electricity
11.
(a)
12.
(a)
13.
(b)
14.
(b)
15.
(b)
16.
(a) The container becomes porous when blue copper sulphate solution is kept into it because iron being more reactive displaces copper from copper sulphate solution and itself form green coloured ferrous sulphate.
(b) Qualities exhibited by Mohan are scientific knowledge, awareness and helpfulness.
17.
Magnesium is found in plants in the form of ionic salts in chlorophyll. Due to its deficiency, plants are unable to produce enough chlorophyll and as a result, leaves develop yellowish colour.
18.
Yes, iron piece will Change its shape as it is a metal. It increases in size and does not break. If a wood log is beaten, it does not Change its shape but it breaks into pieces.
19.
Some food stuffs which have acidic nature such as citrus fruits, lemon pickles and curd should not be stored in container made up of metals such as copper, zinc, aluminium and iron. This is because acid present in food stuffs reacts with these metals to produce toxic compounds which cause food poisoning.
20.
(a) Aluminium is malleable and does not react with food items, so it is used to wrap food items.
(b) Metals are good conductors of heat and electricity. They get hot very soon on passage of current and warm the water. So, immersion rods are made up of metallic substances.
(c) Copper is less reactive than zinc, so it cannot displace zinc from its salt solution.
(d) Sodium and potassium are very reactive, they readily react with air and water, so they are stored in kerosene.
21.
Iron and zinc neither reacts with cold water nor with hot water but reacts with steam to produce hydrogen gas.
22.
Non-metals do not react with water.
23.
(a) Zinc metal reacts with dilute hydrochloric acid to produce hydrogen gas.
(b) Copper metal does not react with dilute hydrochloric acid.
24.
Metals are generally solid, hard, ductile, malleable, sonorous, have metallic lustre and are good conductors of heat and electricity.
25.
The property which allows the metals to be drawn into wires is called ductility.
26.
(a) Firstly, gold is highly malleable and ductile. Secondly, it is not attacked by the gases of air.
(b) We prefer copper wire because it is the better electrical conductor than aluminium. However, silver is the best electrical conductor but it is very expensive.
(c) Silver is the better conductor of heat than copper.
(d) Yes, they are harmful for us because they affect throat and lungs.
27.
Take about 50 mL of water in a beaker and dissolve 5 g of copper sulphate in it to obtain copper sulphate solution (which is blue in colour). Put a clean iron nail in this solution and keep the beaker undisturbed for sometime.
We will find that the blue colour of copper sulphate solution starts fading gradually and the iron nail gets covered with a red-brown layer of copper metal. It is because iron is more reactive than copper, so it displaces copper metal from its solution of copper sulphate. It is the copper metal set free from its compound which forms a red-brown layer on the surface of iron nail. This shows that iron is more reactive than copper.
Copper sulphate + Iron\(\rightarrow \) Iron sulphate + Copper
(Blue solution) (Grey) (Greenish solution) (Red-brown)
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