National Science Olympiad Forum By SOF Olympiad Trainer - Page 410

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Subject :NSO    Class : Class 3

Ans 1:

Class : Class 3
C

Ans 2:

Class : Class 4

Ans 3:

Class : Class 4
C

Ans 4:

Class : Class 5
C

Ans 5:

Class : Class 4
c

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Subject :NSO    Class : Class 4

Ans 1:

Class : Class 5
Answer is hatching.

Ans 2:

Class : Class 8

Ans 3:

Class : Class 4
Incubation C Is the answer

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Subject :NSO    Class : Class 9

Ans 1:

Class : Class 9
yes, (a) is the right answer as due to accelaration by gravity, velocity of any freely falling object will increase continuously. So, (b) is wrong as h1, h2 and h3 are given equal, (c)is wrong too as it is given that covered distance decreases after every 5 seconds, and (d) is also wrong for the same reason.

Ans 2:

Class : Class 9

Ans 3:

Class : Class 9
Option D is the correct answer as the ratio between H1 H2 and H3 is 1: 3 : 5.

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Subject :NSO    Class : Class 9

Few statements regarding the distribution of electrons in the energy shells are given. Which of the following statements is not correct?

A For fourth energy shell (N), the maximum number of electrons is 32 according to 2n2 rule.
B When N is the outermost shell of an atom, it can accommodate a maximum of 8 electrons only.
C The filling of the fourth shell begins even before the third shell is completely filled.
D Fifth shell can accommodate 50 electrons according to 2n2 rule.


Ans 1:

Class : Class 9
(D) is correct

Ans 2:

Class : Class 10
Answer should be either B or c because both of them are incorrect

Ans 3:

Class : Class 9
Option B is wrong . As it is talking of the energy shell. OR might be the question is incorrect as the all the options are correct as per my information.

Ans 4:

Class : Class 9
C should be the answer! a- 2*4^2=32. b-the outermost shell always has 8 to gain perfect stability or become a noble gas. c-wrong, filling always starts from the first, second, third, THEN fourth. d-2*5^2=50

Ans 5:

Class : Class 9
ans should no doubt be c because of the Hund 's rule and also fifth shell does accommodate 50 electrons according to 2n^2 :2*5^2=2*25=50.

Ans 6:

Class : Class 8

Ans 7:

Class : Class 9
(a) is no doubt right, (b) may be wrong, (c) is right and (d) is also right.

Ans 8:

Class : Class 10

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Subject :NSO    Class : Class 9

Ans 1:

Class : Class 9
Volume of the solid cube =(25*25*25)/1000000 cubic metre. Mass of the solid cube = the mass of the body which can be placed on it to completely submerge it Density = 0.1kg/ 125*(10)^6=800kg/m^3

Ans 2:

Class : Class 9
Volume of the solid cube =(25*25*25)/1000000 cubic metre. Mass of the solid cube = the mass of the body which can be placed on it to completely submerge it Density = 0.1kg/ 125*(10)^6=800kg/m^3

Ans 3:

Class : Class 8

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Subject :NSO    Class : Class 9

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Subject :NSO    Class : Class 9

Study the given figure carefully and select the incorrect statement(s).

I. A white ring is formed which is closer to the hydrochloric acid end of the tube because hydrogen chloride fumes diffuse faster than ammonia.
II. Ratio of number of atoms of ammonia to that of hydrogen chloride which combine to form 3.6138 × 1024 atoms of ammonium chloride is 1 : 3.
III. 3.4 g of ammonia combines with 7.3 g of hydrogen chloride to form 10.7 g of ammonium chloride.
IV. If temperature is increased, white ring will be formed exactly in the middle of the tube.
(Given : Atomic mass of H = 1 u, N = 14 u, Cl = 35.5 u)

A II and IV only
B II and III only
C I, II and IV only
D I only


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Subject :NSO    Class : Class 9

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Subject :NSO    Class : Class 4

Ans 1:

Class : Class 4

Ans 2:

Class : Class 6

Ans 3:

Class : Class 4
b ans

Ans 4:

Class : Class 6
Thus ans is c not BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

Ans 5:

Class : Class 6
Thus ans is c not BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

Ans 6:

Class : Class 6
THIS IS NOT POSSIBLE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!Because you can GOOGLE IT.......................................... MY OPINION- Kushagra Chaturvedi

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Subject :NSO    Class : Class 9

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