The energy level diagram of an element is given below. Identify , by doing necessary calculation , which transition corresponds to the emission of a spectral line of wavelength 102.7 nm

Explanation

Given , wavelength of spectral line emitted, `lambda`=102.7 nm = `102.7 xx10^(-9)` m
`therefore` Energy of the emitted photon is
`E=(hc)/lambda=(6.63xx10^(-34)xx3xx10^8)/(102.7xx10^(-9))`
`=1.94xx10^(-18)` J
`=(1.94xx10^(-18))/(1.6xx10^(-19))eV`=12.1eV
Now, `E_A`=-0.85-(-1.5)=0.65 eV
`E_B` =-0.85 -(-3.4)=2.55 eV
`E_C`=-1.5 -(-3.4)=1.9eV
`E_D`=-1.5 -(-13.6)=12.1 eV
So, transition D corresponds to the spectral line of wavelength 102.7 nm as `E=E_D`.