The ratio of wavelengths of the last line of Balmer series and the last line of Lyman series is

The distance of closest approach of an $\alpha$-particle fired towards a nucleus with momentum $p$, is $r$. If the momentum of the $\alpha$-particle is $2p$, the corresponding distance of closest approach is

The wavelength of radiation emitted is ${\lambda _0}$ when an electron jumps from the third to second orbit of hydrogen atom. For the electron jump from fourth to the second orbit of the hydrogen atom, the wavelength of radiation emitted will be

The energy of electron in the nth orbit of hydrogen atom is expressed as${E_n} = \frac{{ - 13.6}}{{{n^2}}}eV$. The shortest and longest wavelength of Lyman series will be

What is the ratio of wavelength of radiations emitted when an electron in hydrogen atom jumps from fourth orbit to second orbit and from third orbit to second orbit

If wavelength corresponding to 2nd line of Lyman series is $\lambda$, then the wavelength corresponding to last line of Balmer series will be

The wavelength of the first line of Balmer series is $6563\,\,{A^0}$. The Rydberg constant for hydrogen is about

First Bohr radius of an atom with $Z = 82$ is $R$. Radius of its third orbit is

The ratio of speed of an electron in ground state in Bohrs first orbit of hydrogen atom to velocity of light in air is

If wavelength corresponding to 2nd line of Lyman series is $\lambda$, then the wavelength corresponding to last line of Balmer series will be

In terms of Rydberg’s constant $R$, the wave number of the first Balmer line is