${r_3}\,\, = \,\,0.529 \times \frac{{{{(3)}^2}}}{1}\,\, = \,\,0.529 \times 9$

 પ્રાથમિક ઉત્તેજીત અવસ્થા એટલે કે $e^- Li^{+2}$ ની દ્વિતીય કક્ષામાં રહેલું છે.

$\begin{gathered}
  {r_2}\,\, = \,\,0.529 \times \frac{{{{(2)}^2}}}{3}\,\, = \,\,0.529 \times \frac{4}{3}\,\,\,\,\,\frac{{{{\left( {{r_3}} \right)}_H}}}{{{{\left( {{r_2}} \right)}_{L{i^{ + 2}}}}}}\,\, = \,\,\frac{{0.529 \times \frac{9}{1}}}{{0.529 \times \frac{4}{3}}} \hfill \\
   = \,\,\frac{{radius\,\,of\,\,{2^{nd}}\,\,excited\,\,state\,\,of\,\,hydrogen}}{{radius\,\,of\,\,{1^{st}}\,\,excited\,\,state\,\,of\,\,L{i^{ + 2}}}}\,\, $

$= \,\,\frac{{{{\left( {{r_3}} \right)}_H}}}{{{{\left( {{r_2}} \right)}_{L{i^{ + 2}}}}}}\,\,

= \,\,\frac{{27}}{4} \hfill \\ 
\end{gathered} $