If $m$ and $e$ are the mass and charge of the revolving electron in the orbit of radius $r$ for a hydrogen atom,the total energy of the revolving electron will be:

Who modified Bohr's theory by introducing elliptical orbits for electron path?

Calculate the wavenumber of a photon emitted during the transition from the orbit of $n=3$ to $n=2$ in a hydrogen atom. $(R_{H} = 109677 \ cm^{-1})$ (in $cm^{-1}$)

The photoelectric behaviour of $K$,$Li$,$Mg$,and $Ag$ metals is shown in the plot below. If light of wavelength $400 \ nm$ is incident on each of these metals,which of them will emit photoelectrons?
[Planck's constant $h=6.626 \times 10^{-34} \ J \ s$; velocity of light $c=3 \times 10^8 \ m \ s^{-1}$; $1 \ eV = 1.6 \times 10^{-19} \ J$]

The difference in radii between the fourth and third Bohr orbits of $He^{+}$ (in $m$) is:

What is the name by which Thomson's atomic model is known?