The 122nm is the largest wavelength in the ultraviolet region of the hydrogen spectrum. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is:

Question

The 122nm is the largest wavelength in the ultraviolet region of the hydrogen spectrum. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is: (A) 802nm (B) 823nm (C) 1882nm (D) 1648nm

Tardigrade Admin · Accepted Answer

The series in the UV region is Lyman series. Longest wavelength corresponds to minimum energy which occurs in the transition from

n = 2

to

n = 1

.
Therefore,

122 = \frac{\frac{1}{R}}{( \frac{1}{1 ^{2}} - \frac{1}{2 ^{2}} )}

... (

i

)
The smallest wavelength in the infrared region corresponds to a maximum energy of the Paschen series.

λ = \frac{\frac{1}{R}}{( \frac{1}{3 ^{2}} - \frac{1}{\infty} )}

.... (

ii

)
Solving equations (

i

) and (

ii

), we get,

λ = 823.5 nm

.

Q. The $122 nm$ is the largest wavelength in the ultraviolet region of the hydrogen spectrum. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is:

$802 nm$

$823 nm$

$1882 nm$

$1648 nm$

Q. The 122nm is the largest wavelength in the ultraviolet region of the hydrogen spectrum. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is:

802nm

823nm

1882nm

1648nm

Q. The $122 nm$ is the largest wavelength in the ultraviolet region of the hydrogen spectrum. The smallest wavelength in the infrared region of the hydrogen spectrum (to the nearest integer) is:

$802 nm$

$823 nm$

$1882 nm$

$1648 nm$