NEETChemistryStructure of Atom
Match List-I with List-II regarding the radius of Bohr orbits ( a₀ is the radius of the first Bohr orbit of a hydrogen atom). List-I (Orbit and Species) List-II (Radius) A. 2^ nd orbit of Li ²⁺ I. 4.5 a₀ B. 3^ rd orbit of He ⁺ II. 2 a₀ C. 4^ th orbit of Be ³⁺ III. 4 3 a₀ D. 2^ nd orbit of He ⁺ IV. 4 a₀ Choose the correct answer from the options given below:
Options
- AA-I, B-III, C-IV, D-II
- BA-III, B-I, C-II, D-IV
- CA-III, B-I, C-IV, D-II
- DA-II, B-IV, C-I, D-III
Correct answer
C. A-III, B-I, C-IV, D-II
Step-by-step solution
The radius of the n^ th Bohr orbit is given by r_n = a₀ n^2 Z . A. For 2^ nd orbit of Li ²⁺ ( n=2, Z=3 ): r = a₀ 2^2 3 = 4 3 a₀ B. For 3^ rd orbit of He ⁺ ( n=3, Z=2 ): r = a₀ 3^2 2 = 4.5 a₀ C. For 4^ th orbit of Be ³⁺ ( n=4, Z=4 ): r = a₀ 4^2 4 = 4 a₀ D. For 2^ nd orbit of He ⁺ ( n=2, Z=2 ): r = a₀ 2^2 2 = 2 a₀ Therefore, the correct match is A-III, B-I, C-IV, D-II. Answer: A-III, B-I, C-IV, D-II