NEETChemistryStructure of Atom
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The wavenumber of the second line of the Paschen series in the hydrogen spectrum is 16 225 R_H . Reason (R): The second line of the Paschen series corresponds to the electron transition from the 5^ th orbit to the 3^ rd orbit. In the light of the above statements, choose the most appropriate answer
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
A. Both (A) and (R) are correct and (R) is the correct explanation of (A)
Step-by-step solution
For the Paschen series, the lower energy level is n₁ = 3 . The first line corresponds to the transition from n₂ = 4 to n₁ = 3 . The second line corresponds to the transition from n₂ = 5 to n₁ = 3 . Thus, Reason (R) is correct. Using the Rydberg formula for the wavenumber: = R_H ( 1 n₁^2 - 1 n₂^2 ) = R_H ( 1 3^2 - 1 5^2 ) = R_H ( 1 9 - 1 25 ) = R_H ( 25 - 9 225 ) = 16 225 R_H Thus, Assertion (A) is correct. Since the transition values provided in Reason (R) are exactly what is used to calculate the wavenumber in Ass