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In this page, we are providing Materials: Metals and Non-Metals Class 8 Extra Questions and Answers Science Chapter 4 pdf download. NCERT Extra Questions for Class 8 Science Chapter 4 Materials: Metals and Non-Metals will help to score more marks in your CBSE Board Exams.

Class 8 Science Chapter 4 Extra Questions and Answers Materials: Metals and Non-Metals

Extra Questions for Class 8 Science Chapter 4 Materials: Metals and Non-Metals with Answers Solutions

Materials: Metals and Non-Metals Class 8 Extra Questions Very Short Answer Type

Question 1.
Name some common metals.
Answer:
Copper, aluminium, iron, silver, gold, etc.

Question 2.
Name some common non-metals.
Answer:
Hydrogen, oxygen, carbon, sulphur, phosphorus, etc.

Question 3.
Give examples of metalloids.
Answer:
Antimony, arsenic, silicon, boron, etc.

Question 4.
Name the property due to which metals shine.
Answer:
Lustre

Question 5.
Name two metals which are soft enough to be cut.
Answer:
Potassium and sodium

Question 6.
Name the property due to which metals can be beaten into thin sheets.
Answer:
Malleability

Question 7.
Which non-metal does conduct heat and electricity?
Answer:
Carbon

Question 8.
Name the property due to which metals can be drawn into wires.
Answer:
Ductility

Question 9.
Name the metal and non-metal which occur in liquid state.
Answer:
Mercury (metal), bromine (non-metal).

Question 10.
Due to which property a bell rings?
Answer:
Sonority

Question 11.
Generally, non-metals are non-lustrous. Name one non-metal which is lustrous.
Answer:
Iodine

Question 12.
State the property of non-metals due to which phosphorus is kept in water.
Answer:
Non-metals do not react with water.

Question 13.
Why some metals displace other metals from their solution?
Answer:
Because of being more reactive than the metals which they displace.

Question 14.
Which metal is used for wrapping food items?
Answer:
Aluminium

Question 15.
Which metal is more reactive: Iron or zinc?
Answer:
Zinc

Question 16.
Which metal is less reactive: Copper or zinc?
Answer:
Copper

Question 17.
Name one metal which does not react with dilute hydrochloric acid.
Answer:
Copper

Question 18.
Whose oxides are basic in nature: Metal or non-metal?
Answer:
Metal

Question 19.
Whose oxides are acidic: Metal or non-metal?
Answer:
Non-metal

Question 20.
Name two metals which do not react with oxygen even at high temperature.
Answer:
Gold and silver

Question 21.
Classify the following into metals and non-metals:
Copper, iron, graphite, sulphur, aluminium, oxygen
Answer:
Metals: Copper, iron, aluminium
Non-metals: Graphite, sulphur, oxygen

Question 22.
Name two physical properties of metals.
Answer:
Malleability and sonority

Question 23.
What happens when metals react with oxygen?
Answer:
Metal oxides are formed.

Question 24.
What happens when magnesium is burnt in air?
Answer:
Magnesium burns with a white dazzling flame and a white powdery magnesium oxide is formed.

Question 25.
What happens when metals react with water?
Answer:
Metals produce their hydroxides or oxides and hydrogen.

Materials: Metals and Non-Metals Class 8 Extra Questions Short Answer Type

Question 1.
What is a metal?
Answer:
Substances having characteristic properties like malleability, ductility, sonority, conductivity, lustre, – and solidness are called metals. For example, aluminium, copper, zinc, iron, etc.

Question 2.
What are non-metals?
Answer:
Substances which are soft and dull, i.e., non-lustrous, non-sonorous, non-ductile, non-malleable and poor conductor of heat and electricity are called non-metals. For example, oxygen, hydrogen, sulphur, etc.

Question 3.
Mention the physical properties of metals.
Answer:
Physical properties of metals are:

• Malleable
• Lustre
• Sonorous
• Ductile
• Solid
• Good conductor of heat and electricity

Question 4.
What are the physical properties of non-metals?
Answer:
The physical properties of non-metals are:

• Non-malleable
• Non-sonorous
• Non-lustrous, i.e., dull in appearance
• Non-ductile
• Poor conductor of heat and electricity

Question 5.
Explain the term ‘malleability’ with suitable examples.
Answer:
Malleability is the property of metals due to which they can be beaten into thin sheets. For example, if we beat or hammer any metal like aluminium, zinc, iron, copper, etc., it become longer and larger but does not break. Thin sheets can be obtained by this process.

Question 6.
What is ductility? Explain with examples.
Answer:
Ductility is one of the properties of metals due to which they can be drawn into wires. For example, aluminium and copper are drawn into wires and used for electrical and different purposes.

Question 7.
Why aluminium is used for wrapping of food items?
Answer:
Aluminium is a metal and hence possesses malleability property. It can be beaten into thin sheets and can be folded into any shape. It is cheaper than other malleable metals and does not react with food items. That is why it is used as wrapping materials for food items.

Question 8.
Why metals are used in ringing bells?
Answer:
Metals have sonority. Due to this property, they can produce ringing sounds. That is why metals are used in ringing bells.

Question 9.
What are the differences between metals and non-metals? Explain on the basis of their physical properties.
Answer:

• Metals are malleable and give thin sheets after hammering whereas non-metals are brittle and give no sheets.
• Metals are ductile and can be drawn into wires whereas non-metals are non-ductile and can’t be drawn into wires.
• Metals are sonorous and used in ringing bells whereas non-metals are non-sonorous and cannot be used in ringing bells.
• Metals are good conductors of heat and electricity while non-metals are poor conductors.

Question 10.
What happen when a copper vessel is exposed to moist air for long? Also write the equation.
Answer:
When a copper vessel is exposed to moist air for long, it acquires a dull green coating. This green material is a mixture of copper hydroxide [Cu(OH)₂] and copper carbonate (CuCO₃). The reaction is as follows:

Question 11.
What happens when a magnesium ribbon is heated in presence of air?
Answer:
When a magnesium ribbon is heated in presence of air, it burns with a white dazzling flame and a white powdery magnesium oxide is formed.

Question 12.
How do metals and non-metals react with water?
Answer:
Metals produce their hydroxides or oxides and hydrogen when they react with water. Sodium and potassium react with cold water along with the production of a large amount of heat. Magnesium react with boiling water and iron with steam. Gold, silver and platinum do not react with water. Non-metals do not react with water.

Question 13.
With the help of equations, explain the reaction of non-metals with oxygen.
Answer:
Non-metals react with oxygen to form acidic oxides. But most of the non-metals reacts with oxygen on ignition.
The equations follow as:

Question 14.
How do metals and non-metals react with acids?
Answer:
Metals react with acids to form respective salts along with evolution of hydrogen gas that burns with a pop sound. The equation are as follows:

There are some metals like copper, silver, gold and platinum that do not liberate hydrogen with acids. Generally, non-metals do not react with acids.

Question 15.
How do metals and non-metals react with bases?
Answer:
Most of the metals do not react with bases. However, some metals like aluminium, lead and zinc react with strong bases like sodium hydroxide (NaOH) to make complex salts and hydrogen.
Generally, non-metals do not react with bases. Sometimes some complex reactions take place between non-metals and bases.

Question 16.
What is a displacement reaction? Give one example.
Answer:
A chemical reaction in which a more reactive metal displaces a less reactive metal is called displacement , reaction. For example, when zinc (Zn) reacts with copper sulphate (CuSO₂), zinc replaces copper being it more reactive than copper. The equation is

Materials: Metals and Non-Metals Class 8 Extra Questions Long Answer Type

Question 1.
Distinguish between metals and non-metals on the basis of their physical properties.
or
Compare the physical properties of metals and non-metals.
Answer:
Difference between metals and non-metals on the basis of their physical properties.

Question 2.
Distinguish between metals and non-metals on the basis of their chemical properties.
or
Compare between metals and non-metals on the basis of their chemical properties.
Answer:
Difference between metals and non-metals on the basis of their chemical properties.

Question 3.
Explain chemical properties of metals with examples.
Answer:
(i) Reaction with oxygen or air: Metals react with oxygen to form basic oxides.
Some metals like potassium and sodium react vigorously with oxygen. For example,

Some noble metals like gold, silver and platinum do not react with oxygen. Iron (Fe) and copper (Cu) get rusted when react in presence of oxygen and water (moist air).

(ii) Reaction with water: Metals react with water to form their oxides or hydroxides. Gold, silver and platinum do not react with water. Some metals like sodium, potassium react vigorously with water. For example,

(iii) Reaction with acids: Metals react with acid to form their salts followed by evolution of hydrogen gas. For example,

Some metals like gold, copper, silver, etc., do not liberate hydrogen gas with acids.

(iv) Reaction with bases: Most of the metals do not react with bases. However some metals like aluminium, zinc and lead react with strong bases like sodium hydroxide to make complex salts and produce hydrogen.

(v) Displacement reactions: More reactive metals displace less reactive metals. For example,

In the above reactions, zinc (Zn) and magnesium (Mg) are more reactive than copper (Cu), hence they replace copper from its solution.

Question 4.
Explain with suitable examples the chemical properties of non-metals.
Answer:
Reaction with oxygen: Non-metals react with oxygen to form acidic oxides. But most of them do this on ignition. For example,

They form negative ions and are good oxidising agents.
Reaction with water: Non-metals do not react with water.
Reaction with acids and bases: Generally, non-metals do not react with acids and bases. How¬ever, sometimes some complex reactions take place between non-metals and bases.

Question 5.
What are main uses of metals?
or
How are metals useful to us?
Answer:
Metals are very useful to us in many ways. For example,
(i) Due to their thermal and electrical conductivity, metals are use to make utensils, cooking vessels, wires and appliances. For example, copper and aluminium are mainly used for these purposes.

(ii) Metals like iron and steel are used in various tools, machinery, pipes, rods, sheets, doors, windows, construction works like bridges, roads, buildings, etc.

(iii) Aluminium is used as packaging and wrapping materials. It is also used in aircrafts and automobiles, etc.

(iv) Metals like gold, silver and platinum are used to make jewellery and other decorating items.

(v) Zinc is used in galvanisation and dry cell and chromium in electroplating.

(vi) Lead is used in making electrodes and batteries.

Question 6.
What are the main uses of non-metals?
or
How are non-metals useful to us?
Answer:
Like metals, non-metals also play an important role in our lives. They help us in many ways. For example,
(i) We breathe oxygen which is the basis of life of all living things including human beings. Without it, no living beings can exist alive on this earth.

(ii) CO₂ which is a non-metal oxide is essential for plants to carry out photosynthesis.

(iii) Non-metals like nitrogen and phosphorus are used in fertilisers for better yield of plant. Phosphorus is used in manufacturing of matchsticks and fireworks.

(iv) Non-metal like iodine is used in the purple coloured solution applied on wounds. Sulphur is also used in preparing skin medicines and making ointment due to its fungicidal properties.

(v) Non-metal like chlorine is used in water purification process. Due to its bleaching properties it is used to make bleaching powder.

(vi) Carbon, a non-metal, is used in most of the fuels.

Question 7.
What is reactivity series? Suggest an activity to arrange sodium, magnesium and copper in the order of their decreasing reactivity.
Answer:
Reactivity series is an arrangement of metals in decreasing order of their reactivity from highest to lowest. The metals occupying the higher positions in the activity series are more reactive in displacing the other metals lying below it from the solutions of their salts.

The activity series is a useful guide for predicting the products of metal displacement reactions. For example, placing a strip of zinc metal in a copper (II) sulphate solution will produce metallic copper and zinc sulphate, since zinc is above copper on the series.

A trip of copper placed into a zinc sulphate solution will not produce an appreciable reaction, because copper is below zinc on the series and can’t displace zinc ions from solution.

Activity to arrange sodium, magnesium and copper in the order of their decreasing reactivity:
(i) Take a pinch of sodium with a forceps and place in a beaker containing water. You will notice that sodium reacts vigorously.

(ii) Take a small piece of magnesium ribbon and add warm water to it. Magnesium reacts with warm water to form magnesium oxide and hydrogen gas. Magnesium reacts very slowly with cold water.

(iii) Take small pieces of copper turnings and add warm water to it. It doesn’t react with warm water also.

Hence, increasing order of reactivity is Na > Mg> Cu.

Materials: Metals and Non-Metals Class 8 Extra Questions HOTS

Question 1.
Why does calcium float in water?
Answer:
The hydrogen gas formed on adding calcium to water sticks to the surface of calcium solid and make it float in water.

Question 2.
Zinc sulphate forms a colourless solution in water. Will you observe any colour on adding copper turning in it?
Answer:
No, because copper is less reactive than zinc and will not be able to displace zinc from its salt solution

Question 3.
A doctor prescribed a tablet to a patient suffering from iron deficiency. The tablet does not look like iron. Explain.
Answer:
The tablet is not made of iron metal, instead it contains a salt of iron.

Question 4.
Ram stored copper sulphate solution in a container made of iron. He observed certain changes after few hours. Can you tell what changes did he observed?
Answer:
Blue colour solution of copper sulphate has changed to green colour of ferrous sulphate. The iron container was found to be corroded from many places. A red powdery deposit of copper sulphate was found on the iron container.

Question 5.
Imagine that gold is reactive like copper. Will it be still wanted? Why or why not?
Answer:
If gold becomes reactive like copper then its use in ornaments will decline. This is because due to its increase reactivity it will lose its shine frequently which in turn will reduce its demand.

Materials: Metals and Non-Metals Class 8 Extra Questions Value Based (VBQs)

Question 1.
Gold is a very precious metal. Pure gold is very soft and is thus not suitable for making jewellery. It is alloyed with either silver or copper to make it hard. But some jewellers mix a large quantity of copper and silver in gold to earn more profit.

(a) What precautions should you take while purchasing gold jewellery?
(b) What standard you must see on gold ornaments?
(c) What value of shopkeeper’s are shown here?
Answer:
(a) We must see the carat of gold jewellery, current price and BIS hallmark on it.
(b) BIS hallmark.
(c) Some shopkeeper’s are greedy, mean, cheater and money minder.

Question 2.
Mercury is largely used in thermometers to measure the temperature. It is a very dangerous metal as its density is very high. If it get into the food chain, it leads to mercury poisoning.
(a) What two precautions you must take while handling equipments containing mercury?
(b) Why mercury is used in thermometers?
(c) Can you suggest other alternatives to mercury thermometers?
Answer:
(a)

• We must handle the equipments carefully and firmly.
• If there is a mercury spill, we must leave the area immediately and inform our parents or teachers.

(b) Mercury is a good conductor of heat. Hence, the slightest change in temperature i° otable when it is used in a thermometer.
(c) Digital thermometer and spirit thermometer.

Letter writing is an essential skill. Despite the prevalence of emails and text messages, everyone has to write letters at some point. Letters of complaint, job applications, thank you letters, letters requesting changes or – making suggestions – the list goes on and on. Encouraging children to write letters from an early age will improve their communication, social and handwriting skills, and teach them what they need to know about writing and structuring letters.

Children are expected to learn how to write letters, notes and messages. They have to be aware of different styles of writing, the use of formal and informal letters, and to select style and vocabulary appropriate to the intended reader.

This grammar section explains English Grammar in a clear and simple way. There are example sentences to show how the language is used. You can also visit the most accurate and elaborate NCERT Solutions for Class 6 English. Every question of the textbook has been answered here.

Informal Letter Writing Topics for Class 6 CBSE Format, Samples Pdf

There are two types of letter

• Informal letters
  
• Formal letters

Informal letters
These are letters to friends and relations, or people you know well.

• Casual and light-hearted tone.
• Lengthier than a formal letter.
• Preferably I side of the page.

Structure:

• The sender’s address should always appear on the top right-hand corner of the page.
• Include telephone number and email if available
• Greeting – There are several variations that can be used depending on how well you know the person: Dear Mary, Hi Mary, Greetings,
• Complimentary close – short comment, for example, Love, Lots of love, With thanks, See you soon

Layout for an Informal letter

Informal Letter Writing Topics Solved Examples for Class 6 CBSE

Informal Letters (Personal)

Question 1.
Write a letter to your sister congratulating her on success in the examination
Answer:
Examination hall,
Ahmedabad
July 05, 20XX,

My Dear Sister,
I am very happy to know that you have passed the secondary school certificate (S.S.C) examination with credit. You got the first division in the examination. I congratulate you on your brilliant success. I am sending you the gift of a wrist watch. May you succeed in every sphere of life. With best wishes,

Yours affectionately
xyz

Question 2.
Write a letter to your mother about the test you have just taken.
Answer:
Examination hall,
Surat
January 03, 20XX,

My Dear Mother
How are you? By the grace of god, I am quite fine. I am sorry that I could not write you earlier. I was taking the second terms papers which ended yesterday. I did well in all the papers. I hope to get 90% marks. I also hope I will stand first in my class. It is possible if you pray for me.

Thank you.

Pay my regards to all at home.

Your loving
son
Raj

Question 3.
Write a letter to your father requesting him to send you some extra funds for payment of hostel dues.
Answer:
Examination hall,
Jaipur
March 11, 20XX,

My Dear Father,
I hope this letter of mine will find you in the best of your health. You will be happy to know that I stood first in my class getting 765 marks. I had to buy some helping books to my course and stationery. They have emptied my pocket. I have run short of money. I shall be grateful to you if you send me extra 1000 rupees for the payment of hostel dues. Pay my regards to all at home. Your loving son, Monish.

Question 4.
Write a letter to your friend thanking him for birthday present he sent for you.
Answer:
House no. 75
Bahubali enclave
Agra
April 14, 20XX

Dear Raghav,
I received your letter yesterday. I am glad to know that you are well. I have just received gift. Thank you very much for your birthday present. The wrist-watch you have sent is splendid. It is very kind of you to give me such a fine present. Hope you are well.

My best regards to your parents.

Yours ever
Hema

Question 5.
Write a letter to your father asking from money to pay the school fee and to buy new books.
Answer:
Flat no. 47
Laxmi nagar
New Delhi
April 14, 20XX

Dear Father,
I received your letter yesterday. I am glad to know that you are well. I need to buy some new books. I could pay my school fees for the last month. So I need rupees 1000. I shall be glad if you send me the said money. With best regards for you and mother.

Yours loving son
Sanjay

Question 6.
Write a letter to your friend inviting him to a picnic at city lake, Udaipur.
Answer:
209, Gandhi nagar
Udaipur
April 14, 20XX

Dear Rohit,
I received your letter yesterday. I am glad to know that you are well. You will be glad to hear that we are going to city lake on February 6 for a picnic. I invite you to join us. Our friends Jony and Rony also will go to city lake with us. City lake is a beautiful place. We shall boat in the Bay together. We shall eat, drink and enjoy together. I am waiting for you.

Yours loving son
Rohan

Question 7.
Write a letter to your friend telling him how you have spent the summer vacation.
Answer:
557, Vivek Vihar
New Delhi
April 14, 20XX

Dear Rajeev,
I have received your letter. You have wanted to know about the how, I have spent my last summer vacation. Now I am writing you about it. You know that education is the backbone of a nation. No nation can prosper without education. But it is a matter of sorrow that most of the people of our country are illiterate and ignorant. They do not know how to read and write.

They have no knowledge of health, family planning and scientific method of cultivation. So I and some of my friends have decided that we would remove illiteracy and ignorance from our village. Finally we implemented our plan and spent the whole vacation in teaching the illiterate villagers. It was an enlightening experience. Villagers thanked us with their kind gestures.

Yours ever
Sameer

Question 8.
Write a letter to your friend inviting him in a birthday party.
Answer:
78, Seema puri
New Delhi
April 14, 20XX

Dear Tanu,
You will be delighted to know that a birthday party has been arranged on the occasion of my 13th birthday at our residence at 6 pm. Only my cousins and a few friends will join the party. A mušical program has also been arranged. I shall be very glad if you take part in it with your camera. Please don’t forget to come. With best regards to you and your parents and younger.

Yours ever
Palak

Question 9.
Write a letter to your friend describing a picnic.
Answer:
486, Chanakya Puri
New Delhi
April 14, 20XX

Dear Renu,
Thank you for your letter. You wanted to know about the picnic that I enjoyed one week ago. Now I am giving you a short description about it. Only the students of our class and some teachers took part in it. We went to Lodhi garden. The place is very rich in natural scenery. We started our journey at 9 in the morning and reached there within an hour. We had a lot of fun there. We played games and ate plenty of food. We also enjoyed the scenery of nature. I personally enjoyed the bus journey to and from the spot. Really it was a very enjoyable and interesting picnic to me. I shall not forget this picnic. With best wishes and love.

Yours ever
Hema

Question 10.
Your father has sent a beautiful gift on your birthday from London. Write a letter to him expressing your feeling of love and admiration for him. You are Sushmita, living at D–7, Amar colony, Lajpat nagar, New Delhi.
Answer:
D-7, Amar Colony
Lajpat Nagar
New Delhi
15th May 20XX

Dear Father,
I received such a nice gift from you on my birthday. My joy knew no bounds. This book gives me a lot of knowledge of vocabulary. Although a good number of my friends and relatives attended the birthday party, yet I missed you all the time. My friends and relatives gifted me many things but your gift of a dictionary is unique in many aspects. This gift is a great source of joy for me. It will help me to cultivate the habit of reading good books. I shall preserve and treasure it throughout my life.

Yours lovingly
Sushmita

Question 11.
In about 100-125 words, write a letter to your friend congratulating him on his success in the examination.
Answer:
10, Prashant Vihar
New Delhi
2nd August 20XX

Dear Sumit,
Please accept my heartiest congratulations on your brilliant success at the Secondary School Examination Board. To secure a high first division is no mean achievement. Though degrees are not now so highly valued as in the past, even so your grand success commands respect. I am sure you will get into a good job in any line you choose. With regards,

Your friend
Prabhat.

Question 12.
In about 100–125 words, write a letter to your friend, inviting him to spend his holidays with you.
Answer:
41, Dwarka II
New Delhi
21st May 20XX

Dear Kailash,
I am very happy to get your nice letter after a long time. Everyone here had been waiting for news about you. Your college is going to close for Puja holidays. Father and I would like you to spend at least the first week of your holidays with us here. We will have a very nice time here.

Days and nights will not be too cold or too hot. We can play, study and walk together. We can enjoy life in full. We are sure you will be able to come. Mother sends you love. Everyone wishes you good luck at the examination. Please do come here.

With love,

Your friend
Suraj

Question 13.
Your friend has invited you to his birthday party. In about 100-125 words, write a letter to him thanking him for it.
Answer:
F-36, R.K. Puram I
New Delhi
2nd August 20XX

Dear Mona,
Thank you very much for kind invitation to your birthday party. My parents have given me consent to spend my day with you. So, wait for me about half-past ten. I will bring my flute and play for you in the garden. My camera will also be with me. You know I produced such wonderful tunes of my flute that charm all my listeners.

With love Your friend
Sima

Question 14.
Your uncle sent you a book for a birthday present. In about 100-125 words, write a letter to your uncle, thanking him for the gift.
Answer:
213, Sarvapriya Vihar
New Delhi
12th December 20XX

Dear Uncle,
Thank you ever so much for the book you have sent me. It was good of you to remember by birthday. You have sent me such an interesting book to read. I have often heard people talk about Kupfer’s Legends of Greece and Rome. I always liked to read it. Now I have it for my own. I feel very proud of it.

I am glad you did not send me an ordinary school – book, most of which are very dry. I began reading the book soon after I received the parcel. It was so exciting that I could not go bed until I finished it. I shall work hard at my English now so that I can read such books easily. Again thanking you for the nice present and the pleasure it has given me.

Your lovingly
Sneha.

Informal Letter Writing Topics Practice Examples for Class 6 CBSE

Informal Letters (Personal)

• Write a letter to your friend inviting him/her to your birthday party
• Write a letter to your friend thanking him/her for attending your birthday party
• You are Sudeep living in school hostel at Surabhi Street, Yojna Nagar. Write a letter to your mother informing her about your performance in the recently held tests.
• Write a letter to your brother thanking him for a birthday gift. You are living at 15/14, Malviya Nagar, New Delhi.
• You are Shiv living at 18, Preet Vihar, Agra Cantt. Your uncle had an official holiday and invited you to show the Taj Mahal which you always wished to see. Write a letter to your friend telling him about your trip to this historical place.
• Write a letter to your friend inviting him to spend Durga Pooja holidays with you.
• On the basis of the picture given below, write a letter to your friend how you got an opportunity to witness a football match.
• You visited a city hospital to see a sick friend. You were pained at the sight of the hospital ward that was ill – maintained. Write a letter to your friend expressing your feeling with the help of the visual here.