Question

Consider the following electronic energy level diagram of $H-$ atom. Photons associated with shortest and longest wavelengths would be emitted from the atom by the transitions labelled

• A. $D$ and $C$ respectively
• B. $C$ and $A$ respectively
• C. $C$ and $D$ respectively
• D. $A$ and $C$ respectively

Answer 1

The correct option is C $C$ and $D$ respectively

For $H-$ atom, $E_1=-13.6eV,E_2=-3.4eV,E_3=-1.5eV,$
$E_4=-0.85eV$ and $E_{\infty }=0$

For $\left(A\right)$
$△E_{\infty 4}=0.85eV$

For $\left(D\right)$
$△E_{43}=0.65eV$

For $\left(C\right)$
$△E_{42}=2.55eV$

For $\left(B\right)$
$△E_{32}=1.6eV$

Thus $C$ corresponds to maximum energy and hence least wavelength and $D$ corresponds to least energy and longest wavelength.