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Model Paper 5 — Chemistry STD 11 Science — Question

Rajasthan BoardEnglish MediumSTD 11 ScienceChemistryModel Paper 51 Mark
MCQ
Assertion (A): In Sommerfeld's model, circular orbit is possible for the electron in K shell.
Reason (R): Electron present in $K$ shell corresponds to principal quantum number $n =1$.
  • A
    Both A and R are true and R is the correct explanation of A.
  • ✓
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • D
    Both A and R are false.
✓

Answer

Correct option: B.
Both A and R are true but R is not the correct explanation of A.
(b) Both $A$ and $R$ are true but $R$ is not the correct explanation of $A$.
Explanation: Sommerfeld's model is an extension of Bohr's model. Electrons in an atom revolve around the nuclei in elliptical orbit. The circular path is a special case of the elliptical orbit. The Association of elliptical orbit with circular orbit explains the fine line spectrum of atoms.

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