According to Bohr's theory which one of the following values of a

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 Multiple Choice QuestionsMultiple Choice Questions

121.

For a crystal, the angle of diffraction (2 θ) is 90° and the second order line has a d value of 2.28 Å. The wavelength (in Å) of X-rays used for Bragg's diffraction is

  • 1.612

  • 2.00

  • 2.28

  • 4.00


122.

The wavelength of a spectral line emitted by hydrogen atom in the Lyman series is 1615R cm. What is the value of n2? ( R= Rydberg constant).

  • 2

  • 3

  • 4

  • 1


123.

The maximum number of sub-levels, orbitals and electrons in N shell of an atom are respectively

  • 4, 12, 32

  • 4, 16, 30

  • 4, 16, 32

  • 4, 32, 64


124.

The wavelengths of electron waves in two orbits is 3 : 5. The ratio of kinetic energy of electrons will be 

  • 25 : 9

  • 5 : 3

  • 9 : 25

  • 3 : 5


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125.

Which one of the following transitions of an electron in hydrogen atom emits radiation of the lowest wavelength?

  • n2 = ∞ to n1=2

  • n2= 4 to n1 =3

  • n2= 2 to n1 =1

  • n2 = 5 to n1=3


126.

Which one of the following conditions is incorrect for a well behaved wave function (Ψ)?

  • Ψ must be fine

  • Ψ must be single valued

  • Ψ must be infinite

  • Ψ must be continuous


127.

The electron affinity values of elements A, B, C and D are respectively -135, -60, -200 and -348 kJ mol-1. The outer electronic configuration of element B is

  • 3s2 3p5

  • 3s3p4

  • 3s2 3p3

  • 3s2 3p2


128.

Which one of the following frequencies of radiation (in Hz) has a wavelength of 600 nm?

  • 2.0 × 1013 

  • 5.0 × 1016 

  • 2.0 × 1014 

  • 5.0 × 1014 


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129.

According to Bohr's theory which one of the following values of angular momentum of hydrogen atom is not permitted?

  • 1.25 hπ

  • hπ

  • 1.5  hπ

  • 0.5 hπ


A.

1.25 hπ

According to Bohr's model, electrons revolve only in those orbits for which angular momentum is an integral multiple of h2π i.e., mvr = nh2π.


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130.

The number of radial nodes of 3s and 2p orbitals respectively are

  • 0, 2

  • 2, 0

  • 1, 2

  • 2, 1


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