Question

The ratio of wavelength of H alpha lyman series and H alpha of pfund Series

Answer 1

Lyman's series is first series while Pfund's series is fifth series among all the spectral line of hydrogen like atom or species.

so, wavelength of H-α Lyman's series is given by, 1/λ = RZ² [1/1² - 1/2² ]

or, λ = 4/3RZ² .....(1)

and wavelength of H-α Pfund's series is given by, 1/λ' = RZ² [ 1/5² - 1/6² ]

= RZ² [ 1/25 - 1/36 ]

= 11RZ²/900

or, λ' = 900/11RZ² .......(2)

we have to find ratio of their wavelength.

so, λ/λ' = (4/3RZ²)/(900/11RZ²)

= 4 × 11/(900 × 3)

= 11/(225 × 3)

= 11/675

hence, answer is 11 : 675