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In Li^(++) , electron in first Bohr orbi...

In `Li^(++)` , electron in first Bohr orbit is excited to a level by a radiation of wavelength `lamda` When the ion gets deexcited to the ground state in all possible ways (including intermediate emissions), a total of six spectral lines are observed. What is the value of `lamda` (Given : `h= 6.63 xx 10^(-34) Js, c = 3 xx 10^(8) ms^(-1)`)

A

`11.4 `nm

B

`9.4` nm

C

`10.8 `nm

D

`12.3`nm

Text Solution

Verified by Experts

The correct Answer is:
C
`6 = (n(n-1))/2 rArr n=4`
`1/lambda =Rz^(2)[1/(1^(2))-1/(4^(2))] = 1.097 xx 10^(7) [1/1 -1/16] xx 9`m
`lambda = 10.8` nm .
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