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 In a sample of H atom all electrons are present in 4th excited state. If e- deexcite then a radiation is observed. How many minimum number atoms are required to observe all spectral lines except lines of Balmer series?

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Important Questions on Atomic Structure

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The ionization energy of gaseous Na atoms is 495.5 kJ mol-1. The lowest possible frequency of light that ionizes a sodium atom is 

(h=6.626×10-34 Js, NA=6.022×1023 mol-1)

EASY
The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with
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The energy of an electron in first Bohr's orbit of H atom is 13.6eV. The energy value of electron in the first excited state of Li 2+ is :
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For any given series of spectral lines of atomic hydrogen, let  Δv-=v-max-v-min  be the difference in maximum and minimum wave number in cm-1

The ratio Δv-Lyman/Δv-Balmar is

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The ground state energy of a hydrogen atom is -13.6 eV. The energy of second excited state of He+ ion in eV is:
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The ratio of the shortest wavelength of two spectral series of hydrogen spectrum is found to be about 9. The spectral series are:
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If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He+ is
HARD
Consider the Bohr's model of a one-electron atom where the electron moves around the nucleus. In the following List-I contains some quantities for the nth orbit of the atom and List-II contains options showing how they depend on n .
 
List - I List - II
(I) Radius of the nth orbit P n-2
(II) Angular momentum of the electron in the nth orbit Q n-1
(III) Kinetic energy of the electron in the nth orbit R n0
(IV) Potential energy of the electron in the nth orbit S n1
  T n2
  U n1/2

Which of the following options has the correct combination considering List-I and List-II?
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If the de Broglie wavelength of the electron in nth Bohr orbit in a hydrogenic atom is equal to 1.5 πa0 (a0 is Bohr radius), then the value of nz is:
HARD
Energy of an electron is given by  E=-2.178×10-18Z2n2 J. Wavelength of light required to excite an electron in a hydrogen atom from level n=1 to n=2 will be :
h=6.62×10-34 Js and c=3.0×108 ms-1
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For the Balmer series, in the spectrum of H atom, v-=RH1n12-1n22, the correct statements among I to IV are,
I As wavelength decreases, the lines in the series converge.
II The integer n1 is equal to 2.
III The lines of the longest wavelength correspond to n2=3.
IV The ionization energy of hydrogen can be calculated from the wave number of these lines.
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For emission line of atomic hydrogen from ni=8 to nf=n, the plot of wave number v- against 1n2 will be: (The Rydberg constant, RH is in wave number unit)
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The radius of the second Bohr orbit, in terms of the Bohr radius, a0, in Li2+ is:
EASY
Which of the following series of transitions in the spectrum of hydrogen atom falls in visible region?
MEDIUM
Consider the Bohr's model of a one-electron atom where the electron moves around the nucleus. In the following List-I contains some quantities for the nth orbit of the atom and List-II contains options showing how they depend on n .
 
List - I List - II
(I) Radius of the nth orbit P n-2
(II) Angular momentum of the electron in the nth orbit Q n-1
(III) Kinetic energy of the electron in the nth orbit R n0
(IV) Potential energy of the electron in the nth orbit S n1
  T n2
  U n1/2

Which of the following options has the correct combination considering List-I and List-II?
MEDIUM
The shortest wavelength of H atom in the Lyman series is λ1. The longest wavelength in the Balmer series of He+ is :
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The difference between the radii of 3rd and 4th  orbits of Li2+ is ΔR1. The difference between the radii of 3rd and 4th  orbits of He+ is ΔR2. Ratio of  ΔR1:ΔR2 is :

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The radius of the second Bohr orbit for hydrogen atom is

(Planck's constant, (h)=6.6262×1034Js; mass of electron =9.1091×10-31kg; charge of electron =1.60210×10-19C; permittivity of vacuum, (0)=8.854185×10-12kg-1m-3A2)
EASY
Which of the following is the energy of a possible excited state of hydrogen?
MEDIUM
Ionisation energy of He + is 19.6× 10 18 J per atom. The energy of the first stationary state (n=1) of Li 2+ per atom is