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COMEDK20269 May 2026Morning ShiftChemistryStructure of AtomActual

The Bohr orbit of the hydrogen atom (n=1) is 0.530 Å. The radius of the first excited state orbit in Å is:

Options

  1. A2.12
  2. B1.66
  3. C0.16
  4. D5.21

Correct answer

A. 2.12

Step-by-step solution

The radius of the n th Bohr orbit for a hydrogen-like species is given by r_n = r₁ n^2 Z . For a hydrogen atom, Z = 1 . The first excited state corresponds to n = 2 . Given r₁ = 0.530 Å. Substituting the values, we get r₂ = 0.530 2^2 1 = 0.530 4 = 2.12 Å. Answer: 2.12

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