Which of the following is true for number of spectral lines in going from Lyman series to Pfund series ?

Options

A. Decreases
B. May increases or decreases
C. Increases
D. Remains the same

Answer

A

Explanation

For lyman series `n_f=1 " and " n_i = 2,3,….oo` and we get the maximum number of spectral lines.
Then we get balmer , paschen , bracket and Pfund series. For Pfund series , `n_f = 5 " and " n_i =6,7,8,…` Thus it has the minimum number of spectral lines. Thus the number of spectral lines decreases.