c
\(\frac{{\text{1}}}{{{\lambda _{{{\text{K}}_\alpha }}}}} = R{(Z - 1)^2}\left( {\frac{1}{{{1^2}}} - \frac{1}{{{2^2}}}} \right) = \frac{{3R{{(Z - 1)}^2}}}{4}\)

\( \Rightarrow \,{(Z - 1)^2} = \frac{4}{{3R{\lambda _{{K_\alpha }}}}}\)

પ્રથમ તત્વ માટે , \({{\text{(}}{{\text{Z}}_{\text{1}}} - 1)^2} = \frac{{4 \times 912 \times {{10}^{ - 10}}m}}{{3 \times 250 \times {{10}^{ - 12}}m}}\)

\( \Rightarrow \,\,{({Z_1} - 1)^2} = 22\,\, \Rightarrow \,\,({Z_1} = 23)\,\)

બીજા તત્વ માટે, \({({Z_2} - 1)^2} = \frac{{4 \times 912 \times {{10}^{ - 10}}m}}{{3 \times 179 \times {{10}^{ - 12}}m}} = \frac{{4 \times 912 \times 100m}}{{3 \times 179}}\)

\( \Rightarrow \,\,{Z_2} - 1 = 26\,\, \Rightarrow \,\,{Z_2} = 27\)

આથી  \({Z_1}\)  અને \({Z_2}\,\)વ્ચ્ચે કોઈ તત્વ હોતું નથી

\(\mathop {23,}\limits_{({Z_1})} \underbrace {\,24,\,\,25,\,\,26\,,\,}_{\operatorname{Re} quired}\mathop {27}\limits_{({Z_2})} \)