Suppose in certine condition only those transition are allowed to hydrogen atoms in which the principal quantum number a changes by`2` (a) Find the smaller wavelength emitted by hydrogen (b) list the wavelength emitted by hydrogen in the visible range `(380 nm to 780 nm)`

Answer

A, B, C, D

Explanation

(a) Here `n=1`, `n=3`,
`E=13.6 ((1)/(4) - (1)/(9))-13.6 xx 8/0`
`=(hc)/(lambda`
or `(13.6 xx 8)/(9) = (4.14 xx 10^-15 xx 3 xx 10^8)/(lambda)`
implies `lambda = (4.14 xx 3 xx 9 xx 10^-7)/(13.6)`
`=0.027 xx 10^-7 = 103 nm`
(b) As 'n' changes by 2 , we may consider
`n=2` to `n=4`
then `E=13.6 xx (1/4-1/16)`
`=2.55 eV`
and ` 255 = 1242`
or, `lambda = 487 nm`,