In this post we will see the science class 8th chapter 4 solution.
You can check the Complete Science Solution here – NCERT Class 8th Science Solutions – Complete Solution List
Chapter 4 Solutions
1. which of the following can be beaten into thin sheets ?
(a) Zinc (b) Phosphorus (c) Sulphur (d) Oxygen
Answer – (a) Zinc
2. 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 – Generally, metals are ductile.
3. Fill in the blanks .
(a) Phosphorus is a 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 a very __reactive__ non-metal.
(b) Metals are __good__ conductors of heat and __electricity__.
(c) Iron is __more__ reactive than copper.
(d) Metals react with acid to produce __hydrogen__ gas.
4. Mark ”T”if the statement is true and”F” if it is false.
(a) Generally, non- metals react with acids. (T/F )
(b) Sodium is a very reactive metal. (T/F )
(c) Copper displaces zinc from zinc sulphate solution . (T/F )
(d) Coal can be drawn into wires. (T/F )
Answer – (i) Generally, non-metals react with acids. (F)
(ii) Sodium is very reactive metal. (T)
(iii) Copper displaces zinc from zinc sulphate solution. (F)
(iv) Coal can be drawn into wires. (F)
5. Some properties are listed in the following Table. Distinguish between metals and non-metals on the basis of these properties.
| Properties |
Metals |
Non-metals |
| 1. Appearance
2. Hardness 3. Malleability 4. Ductility 5. Heat conduction 6. Conduction of electricity |
Answer –
|
Properties |
Metals | Non – metals |
| 1. Appearance
2. Hardness 3. Malleability 4. Ductility 5. Heat conduction 6. Conduction of electricity |
Lustrous
Hard Can be beaten into thin sheets Can be drawn into wires Good conductor of heat Good conductor of electricity
|
Dull
Soft Cannot be beaten into thin sheets Cannot be drawn into wires Poor conductors of heat Poor conductors of electricity. |
6. Give reasons for the following.
(a) Aluminium foils are used to wrap food items.
Answer – Aluminium foils are used to wrap food items because aluminium metal is malleable. Therefore, it can be beaten into thin foils.
(b) Immersion rod of hating liquids are made up of metallic substance.
Answer – Metals are good conductor of heat and electricity . Therefore, immersion rods for heating liquids are made of metallic substances.
(c) Copper cannot displace zinc from its salt solution.
Answer – A metal can displace a less reactive metal from its salt in an aqueous solution. But zinc is more reactive than copper. Therefore, copper cannot displace zinc from its salt solution. Cu(s) + ZnSO4 (aq) →No reaction.
(d) Sodium and potassium are stored in kerosene.
Answer – Sodium and potassium are stored in kerosene because they are highly reactive elements. They can easily catch fire even when in contact with air.
7. Can you store lemon pickle in an aluminium utensil? Explain.
Answer –Lemon pickle cannot be stored in aluminium utensils because lemon pickle contain acids, which can react with aluminium(metal) liberating hydrogen gas. This can lead to the spoiling of the pickle.
8. Match the substances given in a column A with their uses given in Column B.
|
A |
B |
||
| (i) | Gold | (a) | Thermometers |
| (ii) | Iron | (b) | Electric wire |
| (iii) | Aluminium | (c) | Wrapping food |
| (iv) | Carbon | (d) | Jewelry |
| (v) | Copper | (e) | Machinery |
| (vi) | Mercury | (f) | Fuel |
Answer –
|
A |
B |
||
| (i) | Gold | (d) | Jewelry |
| (ii) | Iron | (e) | Machinery |
| (iii) | Aluminium | (c) | Wrapping food |
| (iv) | Carbon | (f) | Fuel |
| (v) | Copper | (b) | Electric wire |
| (vi) | Mercury | (a) | Thermometers |
9. What happens when
(a) Dilute sulphuric acid is poured on a copper plate?
Answer – When dilute sulphuric acid is poured on a copper plate, there will be no reaction between copper and dilute sulphuric acid as copper is less reactive and hence no product will be formed.
(b) Iron nails are placed in copper sulphate solution?
Write word equation of the reactions involved.
Answer – Iron being more reactive displaces copper from copper sulphate solution. In this reaction, the blue colour of copper sulphate fades are there is deposition of copper on the iron nail. 
10. 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 ?
Answer – Add a few drops of water in the test tube containing gas . Now, cover the test tube and shake it well. After, shaking the test the solution with blue litmus and red litmus. It will turn blue litmus red. Thus, the gas is acidic in nature.
(b) Write down word equation of all the reaction taking place in this process.
Answer –
Carbon dioxide react with water to forms carbonic acid, which turns blue litmus paper red. 
11. One day reeta went to jeweller’s shop with her mother gave an old gold jewellery to the goldsmith to polish it . Next day when they brought the jewellery back, they found that there was a slight loss in its weight. Can you suggest a reason for the loss in weight?
Answer – To polish a gold ornament. It is dipped in a liquid called aqua regia (a mixture of hydrochloric acid and nitric acid). On getting the environment of aqua regia, the outer layer of gold dissolves and the inner shiny layer appears. The dissolving of the layer causes a reduction in the weight of the jewellery.
You can check the Complete Science Solution here – NCERT Class 8th Science Solutions – Complete Solution List
You can see other posts here,
- Class 8th NCERT Science Solution Chapter 1 – Crop Production and Management
- Class 8th NCERT Science Solution Chapter 2 – Micro-organisms Friend and Foe
- Class 8th NCERT Science Solution Chapter 3 – Synthetic fibres and plastic
Tags – NCERT science solution for class 8th, 8th class science solution, NCERT science solution, Science solution for 8th class, Science 8th class solution, Solution for 8th class science, 4 chapter science solution class 8th.
