Atoms and Molecules Important Notes


Law of conservation of Mass
It was given by lavoisiier in 1774, according to the law of conservation of mass:Matter is neither created nor destroyed
It means that in a chemical reaction, the total mass of products is equal to the total mass of reactants, there is no change of mass during chemical reaction

It has been found that if 100 grams of calcium carbonate are decomposed completely then 56 grams of calcium oxide and 44 grams of carbon dioxide are formed

CaCo3------------> Cao +    CO2
(100 g)            (56 g)   (44g)

CBSE Class 9 Atoms and molecules:Important Sample paper Questions



Q1.What is meant by Avogadro’s constant?

Q2. Write the formulae of :-
a. Sodium chloride
b. Aluminium oxide
c. Aluminium sulphate
d.Calcium Hydroxide
e.Sodium Carbonate

Why Do We Fall ill Class 9 CBSE Science:Important Questions and Answers

Q1.How are acute diseases different from chronic diseases?
Ans:Acute disease – Diseases which last for short periods of time and are severe are called acute diseases.
Chronic disease – Diseases which are long lasting are called chronic diseases.

CBSE Class 9 Geography Chapter 5 Natural Vegetation and Wildlife Important Question and Answers

 Chapter 5 Natural Vegetation and Wildlife


Q1.Write a short note on the bio diversity in India.Ans• Our country India is one of the twelve mega bio-diversity countries of the world. With
about 47,000 plant species India occupies tenth place in the world and fourth in Asia in
plant diversity.
• There are about15, 000 flowering plants in India which account for 6 per cent in the
world’s total number of flowering plants.
• The country has many non-flowering plants such as ferns, algae and fungi. India also has
89,000 species of animals as well as a rich variety of fish in its fresh and marine waters.

CBSE Class 9 Geography Chapter 6 Population Important Question and Answers

Q:1) Why is population very important in a country? (OR) Why is population a
pivotal element in social studies?
i) The people are important to develop the economy and society. The people make
and use the resources and are themselves resources with varying quality.
ii) It is the point of reference from which all other elements observed and from
which they derive significance and meaning. ‘Resources’ , ‘calamities’ and ‘disasters’
are all meaningful only in relation to human beings.
iii) Their numbers, distributions, growth and characteristics or qualities provide the
basic background for understanding and appreciating all aspects of the
environment.
iv) Human beings are producers and consumers of earth’s resources. Therefore it is
very important to know how many people are there in a country, where do they
live, how and why are their numbers increasing and what are their
characteristics.

Important Sample Paper Questions and Answers of History Class 9 : Peasants and Farmers

Q1.How did the Govt of England React against the Captain Swing movement?

Ans.1.A.Government of England reacted very severely against the actions ofparticipants of the movement.
B.Those suspected of the rioting were rounded up.
C.1976 prisoners were tried up, nine menwere hanged,505 transported-over 450 of them to Australia.
D.644 put behind bars.

Q2.Who was captain Swing?Why was he so famous?
 Ans.2.A.Captain Swing was an imaginary name which was used by the workers to threat the farmers.
B.The workmen wrote letters to farmers to not use threshing machines. Soon, this
imaginary name became a symbol of terror. 
C.Many letters were sent to farmers signed in the name of Captain Swing. 
D.Thus he became a Synonymous to the movement against
 the farmers. 

Q3.What were the main features of Open Field System?
Ans.3.A.The Large part of the countryside was open. It was
divided into private property or enclosure. 
B.Peasants  used  to  cultivate  the  land  around  their  village.  They  allotted  a  fixed
number of strips for farming.
C.A  part  of  the  land  was  kept  as  the  common  land.  This  common  land  was  used
pasture land to collect fuel wood and fruits etc.      

Q.Why did the british govt support the enclosure system?
Ans.4.A.Till  the  middle  of  eighteenth  century  the  enclosure  movement  proceeded  very
slowly.
B.The early enclosures were usually created by indivi
dual landlords.
C.After the mid eighteenth century however the enclosure movement swept through
the countryside changing the English landscape fore
ver.
D.When the price of wool went up in the world market
and the rich farmers wanted to
expand wool production to earn profits.
E.They  were  keen  on  controlling  large  areas  of  land  in  compact  blocks  to  allow
improved breeding. So they began dividing and enclosing common land.
F.From  the  mid  eighteenth  century  the  English  population  expanded  rapidly.  This
meant an increased demand for food grains to feed the population.

Q5.Why was the common land essential for the survival of the poor?
Ans.
All the villagers had access to common land. Here t hey pastured their cows and grazed their sheep, collected fuel wood foe fire and berri es and fruit for food. They fished in the river and ponds, and hunted rabbits in common f orests. So in this way, for the poor, the common land was essential for survival. It supp lemented their meager income, sustained their cattle, and helped them tide over b ad times when crops failed.

Q6.What were the impacts of enclosures on the poor?

Ans.6.A.Enclosures deprived the poor from collecting fire wood from their forests.
B.The poor were prohibited to enter in the grazing land to graze the animals.
C.They were not able to collect fruit or hunt small animals for food.
D.In some areas poor were deprived of their rights and forced to move towards
southern parts.

Q7.Why the British Government has problem from the production of opium in Central India and Rajasthan? 
Ans. A.By 1773, the British Government in Bengal had established a monopoly to trade in
opium.
B.No one else was legally permitted to trade in the product. By the 1820s, the British
found to their horror that opium production in their territories was rapidly declining,
but its production outside the British territories  was increasing.
C.It was being produced in Central India and Rajasthan, within princely states that were not under British control.
D.In these regions, local traders were offering much higher prices ton peasants and
exporting opium to China. To the British this trade was illegal. It was smuggling and it had to be stopped. Government monopoly had to be retained.  

Q18.how did Napoleon Wars make impact on food production?
Ans.A.The  Napoleonic  war  increased  the  demand  for  food  grains  and  the  price  rise. Farmers increased their production as much possible
. B.The end of the wars brought surplus soldiers back to the villages. European food grains too started to come into England. Thus prices come down and agricultural depression started.
C.The  agricultural  depression  reduced the  cultivated area  and  the  number  of employees.

Q19,How did Indian Farmers became ready to grow opium?
Ans.19. A.Indian farmers were provided advances to produce opium.
B.By accepting loan the farmers were forced to grow opium on a specific area of land.
C.The loans were given by the colonial opium agents to the farmers.

Q20.Q.What were the steps taken  by Lin Ze Xu to stop opium Trade?
Ans.a.Lin Ze Xu special commisioner at Canton in 1839, estimated that there were over 4 million opium smokers in China.
b.Lin arrested 1600 men involved in the opium trade and confiscated 11000 pounds of opium.
c.Then he forcedd the foreign factories to hand over their stocks of opium and burnt 20000 crates of opium and blew the ashes to the wind.
d.When he announced that Canton was closed for Foreign Trade, Britain Declared war

Q21.Why were The farmers in Britain Buying New Threshing Machines?
ans.A.The new machines reduced their dependence on the labour.
B.The n ew machines were able to harvest 200 acres of wheat in two weeks.
C.They made the farmers to sow and harvest a big Traits of LAnd.This led to increase in production.
d.It could work as 16 men with Sackers.

CBSE Social Science: Clas IX PEasants and Farmers Important one mark Question and Answers

1.When was a threshing machine of a farmer destroyed?
Ans.1 28th august 1830

Who was captain swing?

CBSE Class 9 Social Science Sample paper Question Answers History and Sport: The Story of Cricket

Q1.What were the reasons behind the shape of the cricket bat, in the shape of hockey stick till the eighteenth century?
Ans..A.Till the middle of the eighteenth century, bats were roughly the same shape as hockey sticks, curving outward at the bottom.

CBSE Class 9 Science: Thrust, Pressure and Floatation Important Questions

Important Questions of Thrust, Pressure and Floatation

Q1.What is meant by buoyancy? Why does an object float or sink when placed on the surface of liquid?

CBSE Class IX History Chapter 7 : History and Sport: The Story of Cricket :Important Notes

 Important Notes of History and Sport:The story of Cricket

CONCEPTS
Cricket grew out of the many stick and ball games played in England. By the 17th century it evolved enough to be recognisable as a distinct game. It became so popular that its fans did not mind to be fined for playing it on Sunday instead of going to church.  

Class 9 History:The Story of Cricket Important Questions and Answers

CBSE CLass 9 History Important Questions and answers
Chapter 7 - The Story of cricket
Q1: Give an example toprove that Englishman gave too much importance to cricket in the 17th century.
Ans.By the seventeenth century, cricket has evolved enough to be recognized as a distinct game and it was popular enough for it’s fans to be fined for playing it on Sunday instead of going to church.

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CBSE Sample Papers for Class 10 Science 2019 Solved Science Sample Question Paper 2019 Set 1 Solved Science Sample Question Paper 2019 ...