Number of possible spectral lines which may be emitted in Brackett series in H atom, if electrons present in `9^(th)` excited level returns to ground level, are

Options

A. 21
B. 6
C. 45
D. 5

Answer

B

Explanation

No. of Spectral lines = `sum Delta n`
`sum 10-1 = 9 +8+7 + 6 + 5 + 4 +3+2 + 1`
No of lines in Brackett series = 6