# Class 9

Explore popular questions from Introduction to Euclid\'s Geometry for Class 9. This collection covers Introduction to Euclid\'s Geometry previous year Class 9 questions hand picked by experienced teachers.

## Mathematics

Introduction to Euclid\'s Geometry

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Q 1. An atom with atomic number 18 and mass number 40, has the following arrangement

18p, 18e, 22n

B

18p, 18e, 40n

C

22p,18e, 18n

D

22p,22e,18n

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Q 2. The isotope of carbon used in radiocarbon dating is

A

{tex}^{12}_6C{/tex}

B

{tex}^{13}_6C{/tex}

{tex}^{14}_6C{/tex}

D

{tex}^{15}_6C{/tex}

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Q 3. Which one of the following is correct electronic configuration of sodium ?

A

2,8

B

8,2,1

C

8,2

2,8,1

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Q 4. Particle in cathode rays have same charge to mass ratio as

A

{tex}\alpha{/tex}-particles

{tex}\beta{/tex}-rays

C

{tex}\gamma{/tex}-rays

D

Protons

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Q 5. Which of the following particles has maximum charge to mass ratio ?

Electrons

B

Protons

C

!-particle

D

Neutrons

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Q 6. Which of the following pairs of species are iso-electronic ?

A

{tex}H_2O, H_2S{/tex}

{tex}NO_3^-,CO_3^{2-}{/tex}

C

{tex}H_3O^+, K^+{/tex}

D

HF, HCI

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Q 7. Which of the following traids represents isotones ?

A

{tex}_6C^{12}, _6C^{13}, _6C^{14}{/tex}

{tex} _{18}Ar^{40}, _{20}Ca^{42}, _{21}Sc^{43}{/tex}

C

{tex} _{18}Ar^{40}, _{20}Ca^{40}, _{21}Sc^{41}{/tex}

D

{tex} _7N^{14}, _8O^{16}, _9F^{19}{/tex}

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Q 8. Which of the following statements is correct ?

{tex}_7N^{14} {/tex} and {tex}_6C^{13}{/tex} are isotones

B

{tex}_7N^{14} {/tex} and {tex}_6C^{14}{/tex} are isotopes

C

{tex}_7N^{14} {/tex} and {tex}_6C^{12}{/tex} are isobars

D

{tex}_7N^{14} {/tex} and {tex}_6C^{15}{/tex} are isotones

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Q 9. Which of the followings statement is not correct ?

A

Isotones are atoms of different elements having same number of neutrons

B

Isotopes are atoms of differenet elements having same number of protons

Isobars are atoms of different elements having same number of neutrons

D

Isotones and isobars are atoms of different elements

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Q 10. When atoms of the gold sheet are bombarded by a beam of {tex}\alpha{/tex}-particles, only a few {tex}\alpha{/tex}-particles get deflected whereas most of them go straight undeflected This is because:

A

the force of attraction on {tex}\alpha{/tex}-particles by the oppositely charged electron is not sufficient

the nucleus occupies much smaller volume as compared to the volume of atom

C

the force of repulsion on fast moving {tex}\alpha{/tex}-particles is very small

D

the neutrons in the nucleus do not have any effect on {tex}\alpha{/tex}-particles

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Q 11. A region in space around the nucleus of an atom where the probability of finding the electron is maximum is called

A

sub-level

B

orbit

orbital

D

electron shell

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Q 12. Which of the following orbital does not make sense?

A

3d

3f

C

5p

D

7s

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Q 13. The maximum number of electrons with clockwise spin that can be accomodated in a f-subshell is

A

10

B

3

C

5

7

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Q 14. Indicate which electronic configuration amongst the following correctly represent SULPHUR atom ?

A

{tex}1s^22s^22p^63s^23p^23d^2{/tex}

B

{tex}1s^22s^22p^63s^23p^24s^2{/tex}

C

{tex}1s^22s^22p^63s^23p^64s^14p^1{/tex}

{tex}1s^22s^22p^63s^23p^4{/tex}

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Q 15. As we move away from nucleus, the energy of orbit

A

decreases

increases

C

remains unchanged

D

none of these

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Q 16. Electronic configuration of calcium atom can be written as

A

{tex}[Ne] 4p^2{/tex}

{tex}[Ar] 4s^2{/tex}

C

{tex}[Ne] 4s^2{/tex}

D

{tex}[Kr] 4p^2{/tex}

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Q 17. Which one of the following pairs of atoms/atom-ion have identical ground state configuration ?

A

Li+ and He+

Cl- and Ar

C

Na and K

D

F+ and Ne

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Q 18. The correct electronic configuration of Cu(29) is

{tex}1s^22s^22p^63s^33p^63d^{10}4s^1{/tex}

B

{tex}1s^22s^22p^63s^23p^53d^{11}4s^1{/tex}

C

{tex}1s^22s^22p^63s^23p^63d^94s^2{/tex}

D

{tex}1s^22s^22p^63s^23p^53d^{10}4s^2{/tex}

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Q 19. The number of d-electrons in Fe{tex}^{2+}{/tex} (atomic number = 26) is equal to that of

p-electrons in {tex}_{10}\mathrm{Ne} {/tex}

B

s-electrons in {tex}_{12}\mathrm{Mg}{/tex}

C

d-electrons in {tex}\mathrm{Fe}{/tex}

D

p-electrons in {tex}\mathrm{CI}{/tex}

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Q 20. Which of the following is the electronic configuration of Cu2+ (Z = 29) ?

A

{tex}[Ar]4s^13d^8{/tex}

B

{tex}[Ar]4s^23d^{10}4p^1{/tex}

C

{tex}[Ar]4s^13d^{10}{/tex}

{tex}[Ar]3d^9{/tex}

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Q 21. Unpaired electrons in {tex}Ni^{++}{/tex}, (Z = 28) is

A

0

2

C

4

D

8

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Q 22. Which of the following electronic configurations is not possible according to Hund's rule ?

A

{tex}1s^22s^2{/tex}

B

{tex}1s^22s^1{/tex}

C

{tex}1s^22s^22p^1_x2p^1_y2p^1_z{/tex}

{tex}1s^22s^22p^2_x2p^1_y2p^0_z{/tex}

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Q 23. Which of the following statement are wrong ?

A

An atom is electrically neutral

An atom & its ion have an unequal number of protons

C

The size of a cation is smaller than that of corresponding atom

D

An atom & its corrosponding anion have equal number of electrons

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Q 24. Which of the following sub-atomic particles is/are present in the nucleus of an atom?

proton

B

electron

C

positron

D

meson

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Q 25. A particle moving with a velocity of 10 m/s is moving with a uniform acceleration of {tex}5 m/s^2{/tex}. What will be the final velocity of the particle after 5 s:

A

30 m/s

B

32 m/s

C

36 m/s

35 m/s