The spectrum of $Li^{2+}$ is similar to that of:

The limiting line in the Balmer series will have a frequency of (Rydberg constant,$R_{\infty} = 3.29 \times 10^{15} \ s^{-1}$)

Which of the following statements is correct regarding the properties of hydrogen-like species?

The separation energy of the electron present in the shell $n = 3$ is $1.51 \ eV$. What is the energy in the first excited state? ............ $eV$

The space between the proton and the electron in a hydrogen atom is:

The binding energy of an $e^-$ in the ground state of a hydrogen atom is $13.6 \ eV$. The energy required to remove an electron from the ground state of a $He^+$ ion is: