$\lambda=4 \times 175\,nm =700\,nm =7000 \mathring A$
જે લાલ રંગની તરંગલંબાઈ છે.
$ \mathrm{Sr}^{2+}(\mathrm{Z}=38), \mathrm{Cs}^{+}(\mathrm{Z}=55), \mathrm{La}^{2+}(\mathrm{Z}=57) \mathrm{Pb}^{2+} $
$ (\mathrm{Z}=82), \mathrm{Yb}^{2+}(\mathrm{Z}=70) \text { and } \mathrm{Fe}^{2+}(\mathrm{Z}=26)$
$(h = 6.63 \times 10^{-34}\,Js)$