Question

The values of n${}_1$ in the Pfund spectral series of hydrogen atom is ________.

• A. 3
• B. 4
• C. 6
• D. 5

Answer 1

Answer: (D)

5

Series	Discovered by	regions	$n_2\to n_1$	Number of lines
lyman	lyman	U.V.region	$n_2=2,3,\mathrm{4...}/n_1=1$	$n_2-1$
Balmer	Balmer	Visible region	$n_2=3,4,\mathrm{5....}/n_1=2$	$n_2-2$
Paschen	Paschen	Infra red (I.R)	$n_2=4,5,\mathrm{6....}/n_1=3$	$n_2-3$
Bracket	Bracket	I.R.region	$n_2=5,6,\mathrm{7....}/n_1=4$	$n_2-4$
Pfund	Pfund	I.R. region	$n_2=6,7,\mathrm{8....}/n_1=5$	$n_2-5$
Humphery	Humphery	far I.R. region	$n_2=7,8,\mathrm{9....}/n_1=6$	$n_2-6$