What is the energy (in $J$ atom$^{-1}$) required for the following process?
$Li^{2+}(g) \to Li^{3+}(g) + e^-$
(Take the ionization energy for the $H$ atom in the ground state as $2.18 \times 10^{-18}$ $J$ atom$^{-1}$)

Given below are two statements.
Statement $I:$ According to Bohr's model of an atom,qualitatively the magnitude of velocity of electron increases with decrease in positive charges on the nucleus as there is no strong hold on the electron by the nucleus.
Statement $II:$ According to Bohr's model of an atom,qualitatively the magnitude of velocity of electron increases with decrease in principal quantum number.
In the light of the above statements,choose the most appropriate answer from the options given below:

The ratio of the radius of the first orbit in hydrogen to the radius of the first orbit in deuterium is .......

The ground state energy of a $H$ atom is given as $-13.6 \, eV$. The energy of the second excited state will be .......... $eV$.

The relation between the stopping potential $(V_0)$ and frequency $(v)$ is correctly represented in $[\phi = \text{Work function}]$

What is the difference in the line spectrum of different atoms compared to the hydrogen atom?