The ratio between kinetic energy and the total energy of the electrons of a hydrogen atom according to Bohr's model is

If an atom has $x$ energy levels,what will be the total number of spectral lines in its emission spectrum?

The wavenumber of the first line $(n_2=3)$ in the Balmer series of hydrogen is $\bar{\nu}_1 \ cm^{-1}$. What is the wavenumber (in $cm^{-1}$) of the second line $(n_2=4)$ in the Balmer series of $He^{+}$?

If the wavelength of the first line of the Balmer series is $656.1 \ nm$,then the wavelength of the second line of this series will be ............. $nm$.

The radii of two of the first four Bohr’s orbits of the hydrogen atom are in the ratio $1 : 4$. The energy difference between them may be

If the radius of the second Bohr orbit of the $He^{+}$ ion is $105.8 \, pm$, what is the radius of the third Bohr orbit of the $Li^{2+}$ ion?