Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Atoms and Nuclei question

2011 · Q138
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /NEET
  3. /Physics
  4. /Atoms and Nuclei
  5. /2011 · Q138

Atoms and Nuclei question

2011 · Q138

NEETPhysicsAtoms and NucleiMCQ+4 / −1
The wavelength of the first line of Lyman series for hydrogen atom is equal to that of the second line of Balmer series for a hydrogen like ion. The atomic number Z of hydrogen like ion is
  1. A
    3
  2. B
    4
  3. C
    1
  4. D
    2
View written solutionFree

Correct answer: D

The wavelength of the first line of lyman series for hydrogen atom is

1λ=R(112−122){1 \over \lambda } = R\left( {{1 \over {{1^2}}} - {1 \over {{2^2}}}} \right)λ1​=R(121​−221​)

The wavelength of the second line of Balmer series for hydrogen like ion is

1λ′=RZ2(122−142){1 \over {\lambda '}} = R{Z^2}\left( {{1 \over {{2^2}}} - {1 \over {{4^2}}}} \right)λ′1​=RZ2(221​−421​)

According to question

λ\lambda λ = λ\lambda λ'

R(112−122)R\left( {{1 \over {{1^2}}} - {1 \over {{2^2}}}} \right)R(121​−221​) = RZ2(122−142)R{Z^2}\left( {{1 \over {{2^2}}} - {1 \over {{4^2}}}} \right)RZ2(221​−421​)

⇒\Rightarrow⇒ 34{3 \over 4}43​ = 3Z216{{3{Z^2}} \over {16}}163Z2​

⇒\Rightarrow⇒ Z = 2

PreviousNext

More from Atoms and Nuclei

  • The power obtained in a reactor using U235 disintegration is 1000 kW. The mass decay of U235 per hour is2011 · MCQ
  • Fusion reaction takes place at high temperature because2011 · MCQ
  • The binding energy per nucleon in deuterium and helium nuclei are 1.1 MeV and 7.0 MeV, respectively. When two deuterium nuclei fuse to form a helium nucleus the energy released in the fusion is2010 · MCQ
  • The mass of a 37​Li Li nucleus is 0.042 u less than the sum of the masses of all its nucleons. The binding energy per nucleon of 37​Li nucleus is nearly2010 · MCQ
  • The energy of a hydrogen atom in the ground state is − 13.6 eV. The energy of a He+ ion in the first excited state will be2010 · MCQ
  • The energy of a hydrogen atom in the ground state is − 13.6 eV. The energy of a He+ ion in the first excited state will be2010 · MCQ
  • An alpha nucleus of energy 21​ mv2 bombards a heavy nuclear target of charge Ze. Then the distance of closest approach for the alpha nucleus will be proportional to2010 · MCQ
  • In a Rutherford scattering experiment when a projectile of charge z1 and mass M1 approaches a target nucleus of charge z2 and mass M2, the distance of closest approach is r0. The energy of the projectile is2009 · MCQ