Tuesday, November 16, 2021

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-10 SUBJECT -SCIENCE CHAPTER-1 CHEMICALS AND REACTIONS AND EQUATIONS.

EVENTS CONVENT HIGH SCHOOL

16/11/2021      CLASS- 10   SESSION 2021-22
SUBJECT :  SCIENCE 

CHAPTER-1 CHEMICALS AND REACTIONS AND EQUATIONS

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Page Number: 6

Question 1
Why should a magnesium ribbon be cleaned before burning in air ?
Answer:
Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.

Question 2
Write the balanced equation for the following chemical reactions.
(i) Hydrogen + Chlorine → Hydrogen chloride
(ii) Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride
(iii) Sodium + Water → Sodium hydroxide + Hydrogen
Answer:
(i) H2 + Cl2 → 2HCl
(ii) 3 BaCl2 + Al2(SO4)3 → BaSO4 + 2 AlCl3
(iii) 2Na + 2H2O → 2NaOH + H2

Question 3
Write a balanced chemical equation with state symbols for the following reactions :
(i) Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and the solution of sodium chloride.
(ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.
Answer:
(i) BaCl2 (aq) + Na2SO4 (aq) → BaSO4(s) + 2NaCl (aq)
(ii) NaOH (aq) + HCl(aq) → NaCl(aq) + H2O(l)

Page Number: 10

Question 1
A solution of a substance ‘X’ is used for white washing.
(i) Name the substance ‘X’ and write its formula.
(ii) Write the reaction of the substance ‘X’ named in (i) above with water.
Answer:
(i) The substance whose solution in water is used for white washing is calcium oxide (or quick lime). Its formula is CaO.
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Intext Questions Page 10 Q1

Question 2
Why is the amount of gas collected in one of the test tubes in text book Activity 1.7 (i.e., electrolysis of water) double of the amount collected in the other? Name this gas. [CBSE 2015 (Delhi)]
Answer:
In Activity 1.7, water is electrolysed to give H2 gas at one electrode and O2 gas at the other electrode.
2H2O(l) → 2H2(g) + O2(g)
Thus two molecules of water on electrolysis give two molecules of hydrogen gas and one molecule of oxygen gas or in other words the amount of hydrogen gas collected would be double than that of oxygen gas.

Page Number: 13

Question 1
Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?
OR
An iron nail is dipped in the solution of copper sulphate for about 30 minutes. State the change in colour observed. Give reason for the change. [CBSE 2015 (Delhi)]
Answer:
When an iron nail is dipped in copper sulphate solution, the displacement reaction takes place. The colour of copper sulphate solution fades due to the formation of light green solution of iron sulphate.
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Intext Questions Page 13 Q1

Question 2
Give an example of a double displacement reaction other than the one given in Activity 1.10 (NCERT Text Book).
Answer:
Sodium hydroxide and hydrochloric acid react to form sodium chloride and water.
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Intext Questions Page 13 Q2

Question 3
Identify the substances that are oxidised and the substances which are reduced in the following reactions.
(i) 4Na(s) + O2(g) → 2Na2O(s)
(ii) CuO (s) + H2(g) → Cu (s) + H2O(l)
Answer:
(i) Substances oxidised is Na as it gains oxygen and oxygen is reduced.
(ii) Substances reduced is Cu as hydrogen is oxidised as it gains oxygen.

NCERT Solutions for Class 10 Science Chapter 1 Textbook Chapter End Questions

Question 1
Which of the statements about the reaction below are incorrect ?
2 PbO(s) + C(s) → 2Pb (s) + CO2(g)
(a) Lead is getting reduced.
(b) Carbon dioxide is getting oxidised.
(c) Carbon is getting oxidised.
(d) Lead oxide is getting reduced.

(i) (a) and (b)
(ii) (a) and (c)
(iii) (a), (b) and (c)
(iv) All
Answer:
(i) (a) and (b)

Question 2
Fe2O3 + 2Al → Al2O3 + 2Fe
The above reaction is an example of a
(a) combination reaction
(b) double displacement reaction
(c) decomposition reaction
(d) displacement reaction
Answer:
(d) Displacement reaction.

Question 3
What happens when dilute hydrochloric acid is added to iron filings ? Tick the correct answer :
(a) Hydrogen gas and iron chloride are produced.
(b) Chlorine gas and iron hydroxide are produced.
(c) No reaction takes place.
(d) Iron salt and water are produced.
Answer:
(a) Hydrogen gas and iron chloride are produced.

Question 4
What is a balanced chemical equation ? Why should chemical equations be balanced ?
Answer:
A balanced chemical equation has an equal number of atoms of different elements in the reactants and products.
The chemical equations should be balanced to satisfy the law of conservation of mass.

Question 5
Translate the following statements into chemical equations and then balance them.
(a) Hydrogen gas combines with nitrogen to form ammonia.
(b) Hydrogen sulphide gas burns in air to give water and sulphur dioxide.
(c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate.
(d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
Answer:
(a) 3H2 (g) + N2 (g) → 2NH3 (g)
(b) H2S (g) + 3O2 (g) → SO2 (g) + 2H2O(l)
(c) 3BaCl2 (aq) + Al2(SO4)3 (aq) → 2AlCl3 (aq) + 3BaSO4 ↓(s)
(d) 2K (s) + 2H2O (l) → 2KOH (aq) + H2 (g)

Question 6
Balance the following chemical equations :
(a) HNO3 + Ca (OH)2 → Ca (NO3)2 + H2O
(b) NaOH + H2SO4 → Na2SO4 + H2O
(c) NaCl + AgNO3 → AgCl + NaNO3
(d) BaCl2 + H2SO4 → BaSO4 + HCl
Answer:
(a) 2HNO3 + Ca(OH)2 → Ca(NO3)2 + 2H2O
(b) 2NaOH + H2SO4 → Na2SO4 + 2H2O
(c) NaCl + AgNO3 → AgCl + NaNO3
(d) BaCl2 + H2SO4 → BaSO4 + 2HCl

Question 7
Write the balanced chemical equations for the following reactions :
(a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
(b) Zinc + Silver nitrate → Zinc nitrate + Silver
(c) Aluminium + Copper chloride → Aluminium chloride + Copper
(d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
Answer:
(a) Ca (OH)2 + CO2 → CaCO3 + H2O
(b) Zn + 2AgNO3 → Zn(NO3)2 + 2 Ag
(c) 2Al + 3 CuCl2 → 2AlCl3 + 3 Cu
(d) BaCl2 + K2SO4 → BaSO4 + 2KCl

Question 8
Write the balanced chemical equation for the following and identify the type of reaction in each case :
(a) Potassium bromide (aq) + Barium iodide (aq) → Potassium iodide (aq) + Barium
(b) Zinc carbonate(s) → Zinc oxide (s) + Carbon dioxide (g) bromide(s)
(c) Hydrogen (g) + Chloride (g) → Hydrogen chloride (g)
(d) Magnesium (s) + Hydrochloric acid (aq) → Magnesium chloride (aq) + Hydrogen (g)
Answer:
(a) 2KBr (aq) + Bal2(aq) → 2Kl(aq) + BaBr2(s)
Type : Double displacement reaction

(b) ZnCO3 (s) → ZnO (s) + CO2 (g)
Type : Decomposition reaction

(c) H2 (g) + Cl2 (g) → 2HCl(g)
Type : Combination reaction

(d) Mg (s) + 2HCl (aq) → MgCl2 (aq) + H2 (g)
Type : Displacement reaction

Question 9
What does one mean by exothermic and endothermic reactions ? Give examples.
Answer:
Exothermic reactions : Those reactions in which heat is evolved are known as exothermic reactions. An exothermic reaction is indicated by writing “+ Heat”on the products side of an equation.
Example :
(i) C (s) + O2 (g) → CO2 (g) + Heat
(ii) N2 (g) + 3H2 (g) → 2NH3 (g) + Heat

Endothermic reactions : Those reactions in which heat is absorbed are known as endothermic reactions. An endothermic reaction is usually indicated by writing “Heat” on the product side of a chemical equation.
Examples :
(i) C (s) + 2S (s) → CS2 (l) – Heat
(ii) N2 (g) + O2 (g) → 2NO(g) – Heat

Question 10
Why is respiration considered an exothermic reaction ? Explain.
Answer:
Respiration is an exothermic process because during respiration glucose combines with oxygen in the cells of our body to form carbon dioxide and water along with the production of energy.
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q10

Question 11
Why are decomposition reactions called the opposite of combination reactions? Write equations for these reactions.
Answer:
In a decomposition reaction, a single compound breaks down to produce two or more simpler substances.
For example:
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q11

While, in a combination reaction, two or more substances simply combine to form a new substance.
For example:
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q11.1

Question 12
Write one equation each for the decomposition reactions where energy is supplied in the form of heat, light or electricity.
OR
Decomposition reactions require energy either in the form of heat or light or electricity for breaking down the reactants. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light and electricity. [CBSE 2015 (Delhi)]
Answer:
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q12

Question 13
What is the difference between displacement and double displacement reactions? Write equations for these reactions.
Answer:
In displacement reactions, a more reactive metal displaces a less reactive metal from its solution. For example,
Fe(s) + CuSO4(aq) → Cu(s) + FeSO4(aq)
This is a displacement reaction where iron displaces copper from its solution.
In double displacement reactions, two reactants in solution exchange their ions. For example,
AgNO3(aq) + NaCl (aq) → AgCl(s) + NaNO3 (aq)
This is a double displacement reaction where silver nitrate and sodium chloride exchange Cl and NO3 ions between them.

Question 14
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
Answer:
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q14

Question 15
What do you mean by a precipitation reaction ? Explain by giving examples.
Answer:
A reaction in which an insoluble solid called precipitate is formed that separates from the solution is called a precipitation reaction.
Example : When a solution of iron (III) chloride and ammonium hydroxide are mixed, a brown precipitate of iron (III) hydroxide is formed.
NCERT Solutions for Class 10 Science Chapter 1 Chemical Reactions and Equations Chapter End Questions Q15

Question 16
Explain the following in terms of gain or loss of oxygen with two examples each:
(a) Oxidation and
(b) Reduction.
Answer:
(a) Oxidation : The addition of oxygen to a substance is called oxidation.
Example :
(i) S(s) + O2(g) → SO2(g) (Addition of oxygen to sulphur)
(ii) 2Mg(s) + O2 (g) → 2MgO(s) (Addition of oxygen to magnesium)

(b) Reduction : The removal of oxygen from a substance is called reduction.
Example: (i) CuO + H2 Heat Cu + H2O
Here, copper oxide is being reduced to copper because oxygen gets removed from copper oxide.

(ii) ZnO + C → Zn + CO

Here, zinc oxide is being reduced to zinc because oxygen gets removed from zinc oxide. 

Class-7 Subject Science Chapter-7 Respiration to Organisms

 EVENTS CONVENT HIGH SCHOOL

16/11/2021      CLASS - 7   SESSION 2021-22
SUBJECT :  SCIENCE

CHAPTER-7 respiration to organism
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Q1. Why does an athlete breathe faster and deeper than usual after finishing the race?
Answer:
During the run, the demand of energy is high but the supply of oxygen to produce energy is limited. Therefore, anaerobic respiration takes places in the muscle cells to fulfill the demand of energy. After finishing the race, an athlete breathe faster and deeper than usual so that more oxygen is supplied to the cells.

Q2. List the similarities and differences between aerobic and anaerobic respiration.
Answer:
Similarity:
(i) In both aerobic and anaerobic respiration, food is broken down to release energy.
(ii) Both takes place inside cells.
(iii) Both produces byproducts.

Differences:

Aerobic RespirationAnaerobic Respiration
(i) It takes place in the presence of oxygen.(i) It takes place in the absence of oxygen.
(ii) Energy is released in higher amount.(ii) Energy is released in lesser amount.
(iii) Carbon dioxide and water are produced as byproducts.(iii) Carbon dioxide and water are produced as byproducts.
(iv) It is a slow process.(iv) It is a fast process.
(v) Examples: Animals and plants cells.(iv) Examples: Human cells, yeast, Bacteria etc.

Q3. Why do we often sneeze when we inhale a lot of dust-laden air?
Answer:
We often sneeze when we inhale a lot of dust-laden air to expel out these foreign particles. These particles get past the hair in the nasal cavity and irritate the lining of the cavity which results in sneezing.

Q4. Take three test-tubes. Fill each of them with water. Label them A, B and C. Keep a snail in test-tube A, a water plant in test-tube B and in C, keep snail and plant both. Which test-tube would have the highest concentration of CO2 ?
Answer:
Test-tube A will have the highest concentration of CO2 because snail will take in oxygen and gives out CO2.
In test-tubes B and C, the CO2 will be utilized by the water plant for synthesizing food and hence there will be less concentration of CO2 in these.

Q5. Tick the correct answer:
(a) In cockroaches, air enters the body through
(i) lungs
(ii) gills
(iii) spiracles
(iv) skin
Answer: (iii) spiracles
(b) During heavy exercise, we get cramps in the legs due to the accumulation of
(i) carbon dioxide
(ii) lactic acid
(iii) alcohol
(iv) water
Answer: (ii) lactic acid
(c) Normal range of breathing rate per minute in an average adult person at rest is:
(i) 9 – 12
(ii) 15 – 18
(iii) 21 – 24
(iv) 30 – 33
Answer: (ii) 15 – 18
(d) During exhalation, the ribs
(i) move outwards
(ii) move downwards
(iii) move upwards
(iv) do not move at all
Answer: (ii) move downwards

Q6. Match the items in Column I with those in Column II:

Column IColumn II
(a) Yeast(i) Earthworm
(b) Diaphragm(ii) Gills
(c) Skin(iii) Alcohol
(d) Leaves(iv) Chest cavity
(e) Fish(v) Stomata
(f) Frog(vi) Lungs and skin
(vii) Tracheae

Answer:

Column IColumn II
(a) Yeast(iii) Alcohol
(b) Diaphragm(iv) Chest cavity
(c) Skin(i) Earthworm
(d) Leaves(v) Stomata
(e) Fish(ii) Gills
(f) Frog(vi) Lungs and skin

Q7. Mark T if the statement is true and F if it is false:
(i) During heavy exercise the breathing rate of a person slows down. (T/ F)
(ii) Plants carry out photosynthesis only during the day and respiration only at night. (T/ F)
(iii) Frogs breathe through their skins as well as their lungs. (T/ F)
(iv) The fishes have lungs for respiration. (T/ F)
(v) The size of the chest cavity increases during inhalation. (T/ F)
Answer:
(i) F
(ii) F
(iii) T
(iv) F
(v) T