The ratio of the frequency corresponding to the third line in the Lyman series of hydrogen atomic spectrum to that of the first line in Balmer series of ${\mathrm{Li}}^{2+ }$spectrum is

For Balmer series in the spectrum of atomic hydrogen, the wave number of each line is given by

$\overline{\mathrm{v}}={\mathrm{R}}_{\mathrm{H}}\left(\frac{1}{{{\mathrm{n}}_1}^2}-\frac{1}{{{\mathrm{n}}_2}^2}\right)$

 where ${\mathrm{R}}_{\mathrm{H}}$ is a constant and ${\mathrm{n}}_1$ and ${\mathrm{n}}_2$ are integers.

Which of the following statement(s) is (are) correct?

1. As wavelength decreases, the lines in the series converge

2. The integer ${\mathrm{n}}_1$ is equal to $2$

3. The ionization energy of hydrogen can be calculated from the wave numbers of these lines

4. The line of longest wavelength corresponds to ${\mathrm{n}}_2=3$

In hydrogen spectrum, the third line from the red end corresponds to which one of the following inter-orbit jumps of the electron for Bohr orbits in an atom of hydrogen ?