In Bohr's model of the hydrogen atom the ratio between the period of revolution of an electron in the orbit n=1 to the period of revolution of the electron in the orbit n=2 is

  • 1:2

  •  2:1

  •  1:4

  •  1:8

A cricket ball of 0.5 kg is moving with a velocity of 100 ms-1. The wavelength associated with its motion is:

  • 1/100cm

  • 6.6 x 10-34m

  •  1.32 x 10-35m

  •  6.6 x 10-28m

The number of electrons in  19 K with quantum numbers n=3; l=0 is/are-

  • 1

  • 2

  • 4

  • 3

The ratio of the difference in energy between the first and second Bohr orbit of H to that between the second and the third Bohr orbit is 

  • 1/2

  • 1/3

  • 4/9

  • 27/5

The number of orbitals that are possible at the L-energy level is

  • 2

  • 4

  • 6

  • 1

The radius of second stationary orbit in Bohr's atom is R. The radius of 3rd orbit will be:-

  • 9R

  • R/4

  • 9R/4

  • 2R

Which of the following is not correctly matched?

  • Energy associated with Bohr's orbit E = -2.18×10-18×Z2n2

  • Energy gap between two orbits ∆E =-hc Z2RH [1n12 -1n22]

  • Kinectic energy of the ejected electron hv = hv0 + 1/2mv2

  • Energy of one mole of photons E = N0hv/C

If the velocity of a particle is reduced to 1/3rd, then percentage increase in its de-broglie wavelength will be:-

  • 100%

  • 200%

  • 50%

  • 33.33%

The magnetic moment order is correctly given in 

  • Fe2+ < Fe3+ < Mn4+ < Cr3+

  •  Cr3+ = Mn4+ < Fe2+ < Fe3+

  •  Cr3+ = Mn4+ < Fe3+ < Fe2+

  •  Fe2+ < Cr3+ < Fe3+ < Mn4+

Bohr's model is not valid for:-

  • H-atom

  • D-atom

  • T-atom

  • He-atom

The maximum wavelength in the Lyman series of He+ ion is-

  • 3R

  • 1/3R

  • 1/R

  • 2R

An atom having mass number 13 has 7 neutrons. What is the atomic number of the atom?

  • 6

  • 7

  • 4

  • 5

 When an electron jumps from n=5 to n=1 in a hydrogen atom, the number of spectral lines obtained is 

  • 3

  • 4

  • 6

  • 10

The frequency of radiation emitted when the electron falls from n=4 to n=1 in a hydrogen atom will be 

(Given ionization energy of H = 2.18 x 10-18J atom-1 and h=6.625 x 10-34Js

  • 2.00 x 1015 s-1

  • 1.54 x 1015 s-1

  • 1.03 x 1015 s-1

  • 3.08 x 1015 s-1

Which one is the wrong statement?

where m= mass of the particle,

v= group velocity of the particle

  • de-Broglie's wavelength is given by λ=h/mv

  • The uncertainty principle is ∆E.∆t≥h/4π

  • Half-filled and fully filled orbitals have greater stability due to greater exchange energy, greater symmetry and more balanced arrangement

  • The energy of 2s-orbital is less than the energy of 2p-orbital in case of hydrogen like atoms.

The group number and electronic configuration of  element Z =114 is 

  • Halogen family, [Rn]5f146d107s27p5

  • Carbon family, [Rn]5f146d107s27p2

  • Oxygen family, [Rn]5f146d107s27p4

  • Nitrogen family, [Rn]5f146d107s27p6

The number of electrons that can be fit into the orbital for which n = 3 and l = 1, is 

  • 2

  • 6

  • 10

  • 14

Which of the following pairs of d-orbitals will have electron density along the axes?

  • dz2,dxz

  •  dxz,dyz

  •  dz2,dx2-y2

  •  dxy,dx2-y2

Two electrons occupying the same orbital are distinguished by

  • Magnetic quantum number

  • Azimuthal quantum number

  • Spin quantum number

  • Principal quantum number

The electronic configurations of Eu (Atomic no. 63), Gd (Atomic no. 64) and Tb (Tb Atomic no. 65) are

  • [Xe]4f65d16s2, [Xe]4f75d16s2 and [Xe]4f96s2

  • [Xe]4f65d16s2, [Xe]4f75d16s2 and [Xe]4f85d16s2

  • [Xe]4f76s2, [Xe]4f75d16s2 and [Xe]4f96s2

  • [Xe]4f76s2, [Xe]4f86s2 and [Xe]4f85d16s2 

The magnetic moment of 2.84 BM can be shown by 

(At. no. Ni = 28, Ti = 22, Cr = 24, Co = 27)

  • Ni2+

  • Ti3+

  • Cr3+

  • Co2+

The number of d-electrons in Fe2+ (Z=26) is not equal to the number of electrons in

which one of the following?

  • s-electrons in Mg (Z=12)

  • p-electrons in Cl (Z=17)

  • d-electrons in Fe (Z=26)

  • p-electrons in Ne (Z=10)

Which is the correct order of increasing energy of the listed orbitals in the atom of

titanium?

  • 3s 4s 3p 3d                   

  • 4s 3s 3p 3d

  • 3s 3p 3d 4s                   

  • 3s 3p 4s 3d

Calculate the energy in Joule corresponding to light of wavelength 45 nm : (Planck's

constant h = 6.63 x 10-34 Js; speed of light c = 3 x 108 ms-1)

  • 6.67 x 1015                             

  • 6.67 x 1011

  • 4.42 x10-15                             

  • 4.42 x 10-18

What is the maximum numbers of electrons that can be associated with the following set

of quantum numbers?

n=3, l = 1 and m=-1

 

  • 10

  • 6

  • 4

  • 2

Based on equation

E = -2.178 × 10-18 J Z2n2 certain conclusions are written. Which of them is not correct?

nucleus is lower than it would be if the electrons were at the infinite distance from the

nucleus

orbit

that the electron is more loosely bound in the smallest allowed orbit

  • The negative sign in equation simply means that the energy of electron bound to the

  • Larger the value of n, the larger is the orbit radius

  • Equation can be used to calculate the change in energy when the electron changes

  • For n=1 the electron has a more negative energy than it does for n=6 which means

The maximum number of electrons in a subshell with l = 3 and n = 4 is

  • 14

  • 16

  • 10

  • 12

The correct set of four quantum numbers for the valence electron of rubidium atom (Z =37) is

  • 5, 1, 1, +1/2               

  • 6, 0, 0, +1/2

  • 5, 0, 0, +1/2               

  • 5, 1, 0, +1/2

The total number of atomic orbitals in fourth energy level of an atom is

  • 16                                 

  • 32

  • 4                                   

  • 8

If the principal quantum number n=6, the correct sequence of filling of electrons will be:

 

 

  • ns→np→(n-1)d→(n-2)f

  • ns→(n-2)f→(n-1)d→np

  • ns→(n-1)d→(n-2)f→np

  • ns→(n-2)f→np→(n-1)d

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