An Electron is revolving around nucleus of charge Ze, if 40.8 eV of energy needed to excite an electron from n=1 to n=2 state. What is value of Z?

Which of the following transition in Balmer series for hydrogen atom will have longest wavelength

Electrons in a certain energy level $n = {n_1}$, can emit ${\rm{3}}\,{\rm{ spectral}}\,{\rm{ lines}}$. When they are in another energy level, $n = {n_2}$. They can emit ${\rm{6}}\,{\rm{ spectral}}\,{\rm{ lines}}$. The orbital speed of the electrons in the two orbits are in the ratio

An atom of element X has 15 protons and 15 electrons. Which of the following statements is true regarding atom X?

Which of the following is true

Which of the following transition in Balmer series for hydrogen atom will have longest wavelength

In a hydrogen atom, if $\lambda_B$ represents the wavelength of the last line of the Balmer series and $\lambda_L$ represents the wavelength of the last line of the Lyman series, then $\lambda_B$ is how many times $\lambda_L$?

Among the following four spectral regions, the photons has the highest energy in

For hydrogen atom, the ratio of the wavelengths of the last line of Balmer series to the second line of Lyman series is:

When an electron jumps from a level $n = 4$ to $n = 1$, momentum of the recoiled hydrogen atom will be

If ${\lambda _{\max }}$ is $6563\,\,{A^0}$, then wavelength of second line for Balmer series will be