The electron in hydrogen atom jumps from `n_2= 4` to `n_1 = 2`. Name the series in which the frequency emitted lies.

The electron in hydrogen atom jumps from n_2= 5 to n_1, = 1 . Name the series in which the frequency emitted lies.

(a) Using the Bohr's model calculate speed of electron in hydrogen atom in the n = 1, 2, and 3 levels. (b) Calculate the orbital period in each of these levels.

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes trnsition from an energy level with n = 4 to an energy level with n = 2 ?

Obtain an expression for the frequency of radiation emitted when a hydrogen atom de-excites form n to n-1 ,show that this frequency equals the classical frequency of revolution of the electron in the orbit.

What is the wavelength of light emitted when the electron in hydrogen atom undergoes transition from an energy level with n = 6 to an energy level with n = 3 ?