Spectrum of $\mathrm{Li}^{2+}$ is similar to that of
Spectrum of $\mathrm{Li}^{2+}$ is similar to that of
$\mathrm{H}$
$\mathrm{Be}$
$\mathrm{He}$
$\mathrm{Ne}$.
Solution
Number of electrons in $\mathrm{Li}^{2+}$ is one similar to the hydrogen atom. One electron system shows similar kind of spectra. Many electron system spectra is complex due to inter-electronic repulsions.