NEETPhysicsAtomic Physics
Match List I with List II. List I List II (A) 2^ nd orbit of H (I) 1 a₀ (B) 3^ rd orbit of He ^+ (II) 3 a₀ (C) 3^ rd orbit of Li ²⁺ (III) 4 a₀ (D) 2^ nd orbit of Be ³⁺ (IV) 4.5 a₀ Choose the correct answer from the options given below:
Options
- A(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- B(A)-(III), (B)-(IV), (C)-(II), (D)-(I)
- C(A)-(III), (B)-(II), (C)-(IV), (D)-(I)
- D(A)-(IV), (B)-(III), (C)-(I), (D)-(II)
Correct answer
B. (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
Step-by-step solution
The radius of the n^ th Bohr orbit of a hydrogen-like species is given by: r_n = a₀ n^2 Z (A) For the 2^ nd orbit of H ( n = 2, Z = 1 ): r = a₀ 2^2 1 = 4 a₀ (B) For the 3^ rd orbit of He ^+ ( n = 3, Z = 2 ): r = a₀ 3^2 2 = 4.5 a₀ (C) For the 3^ rd orbit of Li ²⁺ ( n = 3, Z = 3 ): r = a₀ 3^2 3 = 3 a₀ (D) For the 2^ nd orbit of Be ³⁺ ( n = 2, Z = 4 ): r = a₀ 2^2 4 = 1 a₀ Therefore, the correct matching is (A)-(III), (B)-(IV), (C)-(II), (D)-(I). Answer: (A)-(III), (B)-(IV), (C)-(II), (D)-(I)