Question

The photon radiated from Hydrogen corresponding to $2^{nd}$ line of Lyman series is absorbed by a hydrogen like atom X in $2^{nd}$ excited stat. As a result then, the hydrogen like atom X makes a transition of $n^{th}$ orbit

• A. X =H$e^{+}$; n=4
• B. X =$L{i}^{++}$; n=6
• C. $X=H{e}^{+},n=6$
• D. $X=L{i}^{++},n=9$

Answer 1

Answer: (D)

Energy of $n^{th}$ state in hydrogen is-same as energy of 3$n^{th}$ state in Li${}^{++}$
$\therefore$ 3 $\to$ 1 transition in H would give same energy as the 9 $\to$ 3 transition in Li${}^{++}$ .