CLASS- 8 SUBJECT : CIVIC CHAPTER-3 WHY DO WE NEED A PARLIAMENT,

 EVENTS CONVENT HIGH SCHOOL

10/02/2022      CLASS- 8  SESSION 2021-22
SUBJECT : CIVIC
CHAPTER-3 
WHY DO WE NEED A PARLIAMENT,  

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Question 1.When did India become independent?
Answer:
On 15th August 1947.

Question 2.Which is the most important symbol of Indian democracy and a key feature of the Constitution?
Answer:
The Parliament is an important symbol and key feature of Indian democracy.

Question 3.What is Universal Adult Franchise?
Answer:
It means that all Adult Citizens of the country have the right to vote.

Question 4.In how many years is the Lok Sabha elected?
Answer:
Once in every 5 years.

Question 5.How many elected members are there in Lok Sabha?
Answer:
543 elected members

Question 6.Who selects ministers to work with him/her to implement decisions?
Answer:
The Prime Minister selects ministers.

Question 7.Which is the very important way through which the Parliament controls the executive? Answer:
During Question Hour MPs can elicit information about the working of the government.

Question 8.How are the marginalized given adequate representation?
Answer:
By reserving the seats in the Parliament, the marginalized are given adequate representation

Question Write a brief note on the Rajya Sabha and the Lok Sabha.
Solution:
Rajya Sabha
The Rajya Sabha functions primarily as the representative of the states of India, in the Parliament. There are 233 elected members plus 12 members nominated by the President. The members of the Rajya Sabha are elected by the elected members of the Legislative Assemblies of various states. The Rajya Sabha plays an important role of reviewing and altering the laws initiated by the Lok Sabha.
Lok Sabha
The Lok Sabha, known as the House of the People, with a total membership of 543, is presided over by the Speaker. The country is divided into 543 Lok Sabha constituencies. During a Lok Sabha election, people from different political parties stand for elections. Once elected, these candidates become Members of Parliament or MPs. These MPs together make up the Parliament.

CLASS-7 SUBJECT CIVIC CHAPTER-3 HOW THE STATE GOVERMENT WORKS.

 EVENTS CONVENT HIGH SCHOOL

14/01/2022      CLASS- 7   SESSION 2021-22
SUBJECT :CIVIC 

CHAPTER-3

HOW THE STATE GOVERMENT WORKS

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VERY SHORT ANSWER TYPE QUESTIONS

1. How is the Governor of a state-appointed?  
Answer: The Governor of a state is appointed by the Central Government.

2. Whose responsibility is it to nm various government departments or ministers?
Answer: It is the responsibility of the Chief Minister and other ministers to run various government departments or ministers.

3. How will you define a Legislative Assembly?
Answer: A Legislative Assembly is a place where all the MLAs, from the ruling party as well as the opposition, meet to discuss various things.

4. Define the term ‘government’. 
Answer: The term ‘government’ refers to the government departments and various ministers who head them.

5. Who is the head of the executive?
Answer: The Chief Minister is the head of the executive.

6. Why did the Chief Minister and the minister for health visit Patalpwam district?
Answer: They went to visit the families who had lost their relatives due to the spread of diarrhea. They also visited people in hospitals.

7. Why are press conferences organised?
Answer: Press conferences are oragnised to discuss various current issues.

8. What do you know about wallpaper?
Answer: A wallpaper is an interesting activity through which research can be done on particular topics of interest.

9. Why do people in a democratic set up organise meetings? 
Answer: They do so to voice their opinions and protest against the government if any of its actions is not in their favour.

10. The government works at three levels. Name them.
Answer: The government works at three levels namely

• Local
• State
• Natural

SHORT ANSWER TYPE QUESTIONS

1.Use the terms ‘constituency’ and ‘represent’ to explain who an MLA is and how is the person elected?
Answer:

1. An MLA (Member of the Legislative Assembly) is the person affiliated to a political party or independent who represents a constituency {an area).
2. The person is elected in the following manner:
• A specific area is called a constituency.
• All the adults above 18 years of age are the voters.
• They vote for the candidate of their choice.
• The person who gets the maximum number of votes is declared elected.
• The elected representative is called an MLA.

2. Why should decisions are taken by the Chief Minister and other ministers be debated in the Legislative Assembly?
Answer:
The decisions taken by the Chief Minister and other ministers should be debated in the Legislative Assembly because of the following reasons:

1. The decisions, it is not necessary, taken by the Chief Ministers and ministers are beneficial to one and all.
2. All the MLAs should know about them.
3. Important suggestions may be incorporated in the final decisions.
4. Adversely affecting points are deleted after the debate.
5. The decisions so taken are the decisions of all the members and hence the people.

CLASS-6 SUBJECT -SCIENCE CHAPTER-3 FIBER TO FABRIC

  EVENTS CONVENT HIGH SCHOOL

05/01/2022      CLASS- 6   SESSION 2021-22
SUBJECT :SCIENCE 

CHAPTER-3

FIBER TO FABRIC
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Q.1. Classify the following fibres as natural or synthetic: nylon, wool, cotton, silk, polyester, jute.
Ans. Natural fibres: wool, cotton, jute, silk.
Synthetic fibres: nylon, polyester.

Q.2. State whether the following statements are ‘true’ or false’:
(a) Yam is made from fibres.
(b) Spinning is a process of making fibres.
(c) Jute is the outer covering of coconut.
(d) The process of removing seeds from cotton is called ginning.
(d) Weaving of yam makes a piece of fabric.
(e) Silk fibre is obtained from the stem of a plant.
(g) Polyester is a natural fibre.
Ans.
(a) True
(b) False
(c) False
(d) True
(e) True
(f) False
(g) False

Q.3. Fill in the blanks:
(a) Plant fibres are obtained from____________ and___________ .
(b) Animal fibres are___________ and___________ .
Ans.
(a) cotton plants, jute plants
(b) wool, silk

VERY SHORT ANSWER TYPE QUESTIONS

Q.1. Name two varieties of cloth materials which are commonly used.
Ans. Cotton, silk/wool.

Q.2. What are fabrics?
Ans. Fabrics mean a woven material, textile or other materials resembling woven cloth.

Q.3. Name some fabrics in your surroundings.
Ans. Bed-sheets, blankets, curtains, table clothes, towels and dusters.

Q. 4.  Name the thing which is used to make fabric.
Ans. Yarns.

Q.5. What are yarns made of?
Ans. Yarns are made up of thin strands called fibres.

Q.6. How many types of fibres are there?                                                        ,
Ans. There are two types of fibres:
(i) Natural fibres
(ii) Synthetic fibres

SHORT ANSWER TYPE QUESTIONS

Q.1. What do you observe when you are visiting a nearby tailoring shop?
Ans. In a tailoring shop we observe that there are many cuttings of fabrics left over after stitching. We see that some cuttings are of cotton, some are of silk or wool and some are of synthetic fibres.

Q.2. List the steps involved in the preparation of fabric.
Ans. The following steps are involved in the preparation of fabrics:
(i) Obtaining fibre,
(ii) Preparation of yarn from fibres by spinning,
(iii) When two sets of yarn are involved, yarns are woven on looms to make a fabric. When a single yam is used, the fabric is prepared by knitting.

Q.3. What are natural fibres? Explain with examples.
Ans. The fibres obtained from plants and animals are called natural fibres. For example, cotton from cotton bolls, jute from jute plant, silk from cocoon of silkworm and wool from hair of animals like sheep or goat.

Q.4. What are synthetic fibres?
Ans. The fibres which are made from chemical substances or which are not obtained from the plant and animal sources are called synthetic fibres. For example, polyester, nylon, and acrylic, etc.

Q.5. Explain how jute is obtained from the jute plant.
Ans. The jute plant is normally harvested at flowering stage. The stems of harvested plants are bundled and immersed in water for 10 to 15 days. The stems rot (the process is called retting) and fibres are separated by hand. These fibres are converted into yarns to make fabrics (Fig. 3.10).

Q. 6. What are looms?
Ans. The devices on which weaving of fabrics takes place are called looms. The looms are either hand operated or power operated.

LONG ANSWER TYPE QUESTIONS

Q.1. Describe the process of the formation of yam from cotton wool.
Ans. The cotton wool is obtained from cotton plants. The cotton plants are grown in fields. They are usually grown at the places having black soil and warm climate. The fmits of the cotton plants called cotton bolls are about the size of lemons. After maturing, the bolls burst open and seeds covered with cotton fibres can b,e seen. From the cotton bolls cotton is picked by hands. Fibres are then separated from the seeds by combing. This process is called ginning of cotton. It is done by hand or by machines. These fibres are then converted into yam.

Q.2. Describe the process of spinning and weaving.
Ans. Spinning: The process of making yarn from fibres is called spinning. In this process fibres from a mass of cotton wool are drawn out and twisted. By this fibres come together to form a yarn. Spinning can be done by hand, by takli and charkha. On a large scale, spinning is done with the help of machines.
Weaving: The process of arranging two sets of yarns together t6 make a fabric is called weaving. The process of weaving can be done on looms. The looms are either-hand operated or power operated.

Class-10 Subject -Social Studies (Economics) Chapter-3 Money and Credit

 EVENTS CONVENT HIGH SCHOOL

18/11/2021      CLASS- 10   SESSION 2021-22
SUBJECT :  SOCIAL SCIENCE (ECONOMICS)

CHAPTER-3 MONEY & CREDIT
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Page 52:

Question 1: In situations with high risks, credit might create further problems for the borrower. Explain?
Answer:

1. High-risk situations occur in rural areas because there the main demand for credit is for crop production which involves considerable costs on seeds, fertilisers, pesticides, water, electricity, repair of equipment.
2. There is a minimum stretch of three of four months between the time when farmers buy these inputs and when they sell the crop.
3. Farmers generally take crop loans at the beginning of the season and repay the loan after harvest.
4. Repayment of the loan is crucially dependent on the income from farming.
5. If a crop fails due to shortage of rain or for any other reason, a small farmer has to sell a part of the land to repay the loan.
6. Failure of crops create further problems for the borrowers. Credit does not improve his earnings but leaves him worse off than before. Credit in high risks situations pushes the borrower into a debt trap, a situation from which recovery is very painful.

Question 2: How does money solve the problem of double coincidence of wants? Explain with example of your own.
Answer:
In a barter system where goods are directly exchanged without the use of money, double coincidence of wants is an essential feature. By serving as a medium of exchanges, money removes the need for double coincidence of wants and the difficulties associated with the barter system. For example, it is no longer necessary for the farmer to look for a book publisher who will buy his cereals at the same time sell him books. All he has to do is find a buyer for his cereals. If he has exchanged his cereals for money, he can purchase any goods or service which he needs. This is because money acts as a medium of exchange.

Question 3: How do banks mediate between those who have surplus money and those who need money?
Answer:

1. People hold money as deposits with banks which pay an interest rate on them.
2. People do not withdraw their cash daily.
3. The banks, therefore, hold only 15 percent of their deposits as cash with themselves in order to pay the depositors who might come to withdraw money from the bank on any given day.
4. Since, on any particular day, only some of its many depositors come to withdraw cash, the bank is able to manage with this cash.
5. They use a major portion of the deposits to extend loans to those who need money.
6. The banks make use of deposits to meet the loan requirements of the people.
7. Thus, in this way, the banks mediate between those who have surplus money and those who need money. Banks charge a higher interest rate on loans than what they offer on deposits. The difference between the two is the main source of income of the banks.

Question 4: Look at a 10 rupee note. What is written on top? Can you explain this statement?
“Reserve Bank of India” and “Guaranteed by the Government” are written on top.
Answer:
In India, the Reserve Bank of India issues currency notes on behalf of the central government. The statement means that the currency is authorized or guaranteed by the Central Government. That is, Indian law legalizes the use of the rupee as a medium of payment that can not be refused in a setting transaction in India.

Question 5: Why do we need to expand formal sources of credit in India?
Answer:
We need to expand formal sources of credit in India due to the following reasons :

1. The moneylenders or the agricultural traders charge a much higher interest on loans. They generally charge 5 percent per month whereas the banks charge about 10 to 15 percent per annum. The higher rate of interest does little to increase the income of the borrowers.
2. The farmers who take loans from a trader are forced to sell their crops to him at a low price. As a result of it, the farmers suffer while the traders make a profit by selling grains at a higher prices.
3. Higher interest means the borrower has to pay a major portion of his earnings to repay the interest and principal of the loan. This sometimes leads to debt trap for the borrowers.
4. On the other hand, banks and cooperatives charge less interest and do not exploit the borrowers. Under these circumstances, there is need for expansion of formal sources of credit in India. It is also necessary that everyone receives these loans.
5. This would also lead to higher incomes and many people could then borrow cheaply for a variety of needs. The formal credit should be distributed equally to benefit the poor from the cheaper loan.
6. It may be added that cheap and affordable credit is crucial for the development of the country.

Question 6: What is the basic idea behind the SHGs for the poor? Explain in your own words.
Answer:
The basic behind the SHGs is to provide a financial resource for the poor through organizing the rural poor especially women, into small Self Help Groups. They also provide timely loans at a responsible interest rate without collateral. Thus, the main objectives of the SHGs are:

1. To organize rural poor especially women into small Self Help Groups.
2. To collect savings of their members.
3. To provide loans without collateral.
4. To provide timely loans for a variety of purposes.
5. To provide loans at a responsible rate of interest and easy terms.
6. Provide a platform to discuss and act on a variety of social issues such as education, health, nutrition, domestic violence, etc.

Question 7: What are the reasons why the banks might not be willing to lend to certain borrowers?
Answer:
The banks might not be willing to lend certain borrowers due to the following reasons:

• Banks require proper documents and collateral as security against loans. Some persons fail to meet these requirements.
• The borrowers who have not repaid previous loans, the banks might not be willing to lend them further.
• The banks might not be willing to lend those entrepreneurs who are going to invest in the business with high risks.
• One of the principal objectives of a bank is to earn more profits after meeting a number of expenses. For this purpose, it has to adopt a judicious loan and investment policies which ensure fair and stable return on the funds.

Question 8: In what ways does the Reserve Bank of India supervise the functioning of banks? Why is this necessary?
Answer:
The Reserve Bank of India monitors the amount of money that banks loan out, and also the amount of cash balance maintained by them. It also ensures that banks give out loans not just to profiteering businesses but also to small cultivators, small scale industries, and small borrowers. Periodically, banks are supposed to submit information to the RBI on the amounts lent, to whom, and at what rates of interest.

This monitoring is necessary to ensure that equality is preserved in the financial sector, and that small industry are also given an outlet to grow. This is also done to make sure that banks do not loan out more money than they are supposed to, as this can lead to situations like the Great Depression of the 1930s in the USA, which greatly affected the world economy as well.

Question 9: Analyse the role of credit for development.
Answer:
The role of credit for development is very significant as mentioned below:

• It helps in increasing economic activities of the borrowers.
• If credit is made available to the poor people on reasonable terms and conditions, they can improve their economic condition. This will help in the over all development.
• Credit may increase the activities in the secondary sector e., manufacturing sector. Thus, with credit people could grow crops, do business, set up small-scale industries. They could set up new industries or trade in goods. Therefore, credit is crucial for the country’s development.

Question 10: Manav needs a loan to set up a small business. On what basis will Manav decide whether to borrow from the bank or the moneylender? Discuss.
Answer: Manav will decide whether to borrow from the bank or the moneylender on the basis of the following terms of credit:

• rate of interest
• requirements availability of collateral and documentation required by the banker.
• mode of repayment.

Depending on these factors and of course, easier terms of repayment, Manav has to decide whether he has to borrow from the bank or the moneylender.

Question 11: In India, about 80 percent of farmers are small farmers, who need cultivation.
(a) Why might banks be unwilling to lend to small farmers?
(b) What are the other sources from which the small farmers can borrow?
(c) Explain with an example of how the terms of credit can be unfavorable for the small farmer.
(d) Suggest some ways by which small farmers can get cheap credit.
Answer:
(a) The banks might be unwilling to lend to small farmers because the farmers usually take crop loan at the beginning of the season and repay the loan after harvest. Repayment of loan is dependent on the income from farming. And in case of crop failure, repayment becomes impossible. In such cases, the recovery of loan from the small farmers becomes very difficult. The small farmers have to sell part of the land to repay the loan that is why banks do not want to give loans to small farmers.

(b) Small farmers usually borrow from moneylenders or agricultural traders.

(c) In case of failure of crops, it becomes impossible for small farmers to repay the loan by selling their crops. Thus in order to repay, the small farmers sell a part of the land. This leads to worsening of their condition. Sometimes, small farmers give collateral or security against loans. The collateral generally consists of land, building, vehicles, livestock. In case of nonpayment of loan, the lender may sell the collateral to recover loan. Under above conditions, the terms of credit become unfavourable for the small farmers.

(d) Besides banks, the other major source of cheap credit in rural areas are the cooperative societies or cooperatives. Members of a cooperative society, pool their resources for cooperation in certain areas. The cooperative accepts deposits from its members. With these deposits as collateral, the cooperative obtains loan from the bank. These funds are used to provide loans to members.

Question 12: Fill in the blanks:

1. Majority of the credit needs of the __________households are met from informal sources.
2. __________costs of borrowing increase the debt-burden.
3. __________issues currency notes on behalf of the Central Government.
4. Banks charge a higher interest rate on loans than what they offer on __________.
5. _________is an asset that the borrower owns and uses as a guarantee until the loan is repaid to the lender.

Answer:

1. Majority of the credit needs of the poor households are met from informal sources.
2. High costs of borrowing increase the debt-burden.
3. Reserve Bank of India issues currency notes on behalf of the Central Government.
4. Banks charge a higher interest rate on loans than what they offer on deposits.
5. Collateral is an asset that the borrower owns and uses as a guarantee until the loan is repaid to the lender.

Question 13: Choose the most appropriate answer.
(i) In an SHG most of the decisions regarding savings and loan activities are taken by
(a) Bank.
(b) Members.
(c) Non-government organization.

(ii) Formal sources of credit do not include
(a) Banks.
(b) Cooperatives.
(c) Employers.
Answer:
(i) (b)
(ii) (c)

CLASS-9 SUBJECT-SOCIAL SCIENCE (HISTORY) CHAPTER-3 NAZIMS AND THE RISE OF HITLER

 EVENTS CONVENT HIGH SCHOOL

16/11/2021      CLASS- 9   SESSION 2021-22
SUBJECT :  SOCIAL SCIENCE (HISTORY)

CHAPTER-3 NAZIMS AND THE RISE OF HITLER
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Question-1

Describe the problems faced by the Weimar Republic.
Solution:
The problems faced by the Weimar Republic were as follows:

1. The Weimar constitution had Inherent drawbacks making the Weimar Republic fragile.
   • One was proportional representation which made it difficult for any party to get a majority leading to coalition governments.
   • Article 48, which gave the President the power to rule by decree, suspend civil rights and to impose an emergency.
     People lost confidence in a democratic parliamentary system.
2. The Weimar Republic was not received well by the people because of the terms it was forced to accept at Versailles at the end of the First World War. It was a harsh and humiliating treaty that Germany had to accept with the Allies. Many people held the Weimar Republic responsible for the defeat in the war and for accepting the terms of the Treaty of Versailles,
3. In 1923 Germany refused to pay reparation payments and the French occupied its leading industrial area, the Ruhr, to claim their coal. Germany offered passive resistance and printed paper currency. With too much paper currency in circulation, the value of the German mark fell. The situation is called hyperinflation.
4. The Weimar Republic had to face another economic crisis. The USA Withdrew her support when Wall Street Exchange crashed in 1929. German economy was the worst hit by the economic crisis. Workers lost their jobs or were paid reduced wages. The number of unemployed reached 6 million. The economic crisis created a feeling of fear among the people.

Question-2
Discuss why Nazism became popular in Germany by 1930.
Solution:
In 1919 Adolph Hitler took over the German Workers’ Party and called it the Nazi Party, giving birth to Nazism in Germany.
During the Great Economic Depression Nazism became very popular. The Nazi Propaganda which was very unique helped in making Nazism very popular. In his powerful speeches, Hitler promised to build a strong nation, restore the dignity of the Germans and provide employment for all. Numerous public meetings were held by the Nazi Party to instil unity among the people.

The red banners, the Nazi salute, and the rounds of applause attracted the people and Nazism became very popular. The Meetings projected Hitler as a saviour of Germany. The German people who were shattered after the First World War believed him.

Question-3
What are the peculiar features of Nazi thinking?
Solution:
The peculiar features of Nazi thinking are as follows.

1. Nazi ideology was the same as Hitler’s worldview. According to this there was no equality between people but only a racial hierarchy. In this view blond, blue-eyed Nordic German Aryans were at the top called ‘desirables’ while Jews (undesirables) were placed at the lowest rung. Hitler’s racism was influenced by thinkers like Charles Darwin and Herbert Spencer. The Nazi argument was simple: ‘The strongest race would survive, the weak ones would perish’.
2. Hitler believed in Lebensraum or living space. New territories had to be conquered to increase the living space.
3. Nazis wanted a society of pure and healthy Nordic Aryans. It meant that even those Germans who were seen as impure or abnormal had no right to live. Under the Euthanasia Programme, the Nazi condemned to death many Germans, who were mentally or physically unfit.
4. As soon as Hitler came to power he tried to eliminate the undesirables and the gypsy. The Nazis proceeded to realise their murderous racial ideals.
5. Jews remained the worst sufferers in Nazi Germany. They were called ‘undesirables’. Hitler’s hatred for Jews was based on pseudoscientific theories of race, which held conversion was no solution. They should be completely eliminated.

Question-4
Explain why Nazi propaganda was effective in creating a hatred for Jews.
Solution:
Films were made to create hatred for the Jews. The film, ‘The Eternal Jew’, showed the Jews with flowing beards and dressed in kaftans. The Jews were referred to as vermin, rats, and pests. Nazi propaganda compared the Jews to rodents.

Orthodox Jews were stereotyped as killers of Christ and money lenders. Stereotypes about Jews were even popularised through maths classes. Children were taught to hate the Jews. The Nazi propaganda against the Jews was so effective that people felt anger and hatred surge inside them when they saw someone who looked like a Jew.

Question-5
Explain what role women had in Nazi society. Return to Chapter 1 on the French Revolution. Write a paragraph comparing and contrasting the role of women in the two periods.
Solution:
In Nazi Germany, boys were told to be aggressive and steel-hearted, girls were told that they had to become good mothers and rear pure-blooded Aryan children. Girls had to protect the purity of German race. They had to look after their homes and Nazi values had to be taught to the children.

Women who produced ‘desirable children’ were awarded. They got better treatment in hospitals, and got concessions in shops, on theatre tickets and railway fares. Honour crosses were awarded to women. A bronze cross was awarded to women for four children, silver cross for six children and gold for eight or more children.

Question-6
In what ways did the Nazi state seek to establish total control over its people?
Solution:
The Nazi state tried to establish total control over its people. Special forces were created to control the society, in the way Nazis wanted. Apart from SA or the Storm Troopers, and regular police, who wore a green uniform, these included the Gestapo (secret state police) and SS (the protection squads), criminal police, and the Security Service (SD). They were given extra-constitutional powers, that gave the Nazi state its reputation as the most dreaded criminal state. People were tortured in Gestapo chambers and sent to concentration camps. People were arrested without any legal procedures.

CLASS-9 SUBJECT SCIENCE CHAPTER-3 ATOMS AND MOLECULES

 EVENTS CONVENT HIGH SCHOOL

08/11/2021      CLASS- 9   SESSION 2021-22
SUBJECT :  SCIENCE

CHAPTER-3
ATOMS AND MOLECULES

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Question 1. In a reaction 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass carbonate.
Answer.

Class 9 Science NCERT Textbook Page 32
Question 1. In a reaction 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9 g water and 8.2 g of sodium etkanoate. Show that these observations are in agreement with the law of conservation of mass carbonate.
Answer:

Question 2. Hydrogen and oxygen combine in the ratio of 1 : 8 by mass to form water. What mass of oxygen gas would be required to react completely with 3 g of hydrogen gas?
Answer: Ratio of H : O by mass in water is:
Hydrogen : Oxygen —> H2O
∴ 1 : 8 = 3 : x
x = 8 x 3
x = 24 g
∴ 24 g of oxygen gas would be required to react completely with 3 g of hydrogen gas.

Question 3. Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?
Answer: The postulate of Dalton’s atomic theory that is the result of the law of conservation of mass is—the relative number and kinds of atoms are constant in a given compound. Atoms cannot be created nor destroyed in a chemical reaction.

Question 4. Which postulate of Dalton’s atomic theory can explain the law of definite proportions?
Answer: The relative number and kinds of atoms are constant in a given compound.

Class 9 Science NCERT Textbook Page 35
Question 1. Define the atomic mass unit.
Answer: One atomic mass unit is equal to exactly one-twelfth (1/12th) the mass of one atom of carbon-12. The relative atomic masses of all elements have been found with respect to an atom of carbon-12.

Question 2. Why is it not possible to see an atom with naked eyes?
Answer: Atom is too small to be seen with naked eyes. It is measured in nanometres.
1 m = 109 nm

NCERT Textbook Questions – Page 39
Question 1. Write down the formulae of
(i) Sodium oxide
(ii) Aluminium chloride
(iii) Sodium sulphide
(iv) Magnesium hydroxide
Answer: The formulae are

Question 2. What is meant by the term chemical formula?
Answer: The chemical formula of the compound is a symbolic representation of its composition, e.g., chemical formula of sodium chloride is NaCl.

Question 3. How many atoms are present in a
(i) H2S molecule and
(ii) P043- ion?
Answer: (i) H2S —> 3 atoms are present
(ii) P043- —> 5 atoms are present

NCERT Textbook Questions – Page 40
Question 1. Calculate the molecular masses of H2, O2, Cl2, C02, CH4, C2H2,NH3, CH3OH.
Answer: The molecular masses are:

Question 2.Calculate the formula unit masses of ZnO, Na2O, K2C03, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.
Answer: The formula unit mass of
(i) ZnO = 65 u + 16 u = 81 u
(ii) Na2O = (23 u x 2) + 16 u = 46 u + 16 u = 62 u
(iii) K2C03 = (39 u x 2) + 12 u + 16 u x 3
= 78 u + 12 u + 48 u = 138 u

Class 9 Science NCERT Textbook Page 42
Question 1. If one mole of carbon atoms weigh 12 grams, what is the mass (in grams) of 1 atom of carbon?
Answer:

Question 2. Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given atomic mass of Na = 23 u, Fe = 56 u)?
Answer:

Questions From NCERT Textbook for Class 9 Science

Question 1. A 0.24 g sample of compound of oxygen and boron was found by analysis to contain 0.096 g of boron and 0.144 g of oxygen. Calculate the percentage composition of the compound by weight.
Answer: Boron and oxygen compound —> Boron + Oxygen
0.24 g —> 0.096 g + 0.144 g

Question 2. When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 3.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?
Answer: The reaction of burning of carbon in oxygen may be written as:

It shows that 12 g of carbon bums in 32 g oxygen to form 44 g of carbon dioxide. Therefore 3 g of carbon reacts with 8 g of oxygen to form 11 g of carbon dioxide. It is given that 3.0 g of carbon is burnt with 8 g of oxygen to produce 11.0 g of CO2. Consequently 11.0 g of carbon dioxide will be formed when 3.0 g of C is burnt in 50 g of oxygen consuming 8 g of oxygen, leaving behind 50 – 8 = 42 g of O2. The answer governs the law of constant proportion.

Question 3. What are poly atomic ions? Give examples.
Answer: The ions which contain more than one atoms (same kind or may be of different kind) and behave as a single unit are called polyatomic ions e.g., OH–, SO42-, CO32-.

Question 4. Write the chemical formulae of the following:
(a) Magnesium chloride
(b) Calcium oxide
(c) Copper nitrate
(d) Aluminium chloride
(e) Calcium carbonate.
Answer: (a) Magnesium chloride
Symbol —> Mg Cl
Change —> +2 -1
Formula —> MgCl2
(b) Calcium oxide
Symbol —> Ca O
Charge —> +2 -2
Formula —> CaO
(c) Copper nitrate
Symbol —> Cu NO
Change +2 -1
Formula -4 CU(N03)2
(d) Aluminium chloride
Symbol —> Al Cl
Change —> +3 -1
Formula —> AlCl3
(d) Calcium carbonate
Symbol —> Ca CO3
Change —> +2 -2
Formula —> CaC03