In any Bohr orbit of the hydrogen atom,the ratio of kinetic energy to potential energy of the electron is

If one takes into account the finite mass of the proton,then the correction to the binding energy of the hydrogen atom is approximately (take,mass of proton $= 1.60 \times 10^{-27} \, kg$ and mass of electron $= 9.10 \times 10^{-31} \, kg$) (in $\%$)

The radius of the innermost orbit of a hydrogen atom is $5.3 \times 10^{-11} \ m$. The radius of the fourth allowed orbit of the hydrogen atom is: (in $Å$)

In the third orbit of a hydrogen atom,if the de Broglie wavelength of the electron is $\lambda$,then the radius of the third orbit is:

The Hitomi satellite recently observed the Lyman alpha emission line ($n=2$ to $n=1$) of hydrogen-like iron ion (atomic number of iron is $26$) from the Perseus galaxy cluster. The wavelength of the line is closest to ............... $\mathring{A}$.

If $\lambda_{1}$ and $\lambda_{2}$ are the wavelengths of de-Broglie waves for electrons in the first and second Bohr orbits in a hydrogen atom,then the ratio $\left(\frac{\lambda_{1}}{\lambda_{2}}\right)$ is equal to: