Absorption Spectrum of Hydrogen

[aim1732]

When white radiation is passed through a sample of hydrogen gas(atoms assumed actually) why are absorption lines observed in Lyman series only?
The corresponding photon energy range for visible light(380-780nm) are 1.59-3.27eV which should cause transitions of electrons in the first excited state(n=2) only.This should give absorption spectrum lines in Balmer series.Am I wrong?
Please,I am studying Bohr's model and any explanation involving quantum physics(except of course the very basics) will not be clear to me.

 

[kuruman]

In what energy level should a hydrogen atom in the sample be in order to absorb a photon in the Balmer series? That is, what should the initial value of n be?

 

[aim1732]

Second,of course(n=2).
But it is not mentioned in the question that the atoms are in ground state hence I assumed a random distribution. Anyways it takes a minimum of 10.2eV to excite an electron from n=1 shell which is clearly not available for photons of visible light.

 

[kuruman]

Second,of course(n=2).
But it is not mentioned in the question that the atoms are in ground state hence I assumed a random distribution. Anyways it takes a minimum of 10.2eV to excite an electron from n=1 shell which is clearly not available for photons of visible light.

Correct. Although the question does not mention it, you are supposed to figure it out and you have. The question also doesn't mention that the sample of hydrogen is bathed in 10.2 eV photons, therefore it is a good assumption that it is not.

 

[Peymon]

It exactly depends on the state of the atom .For Lyman Series the shortest wave length is 91.2 nm correspond to 13.6 ev and the longest is 121.5 nm correspond to 10.2 ev and all other wavelength in this series are between these 2 limits.So it is clear that this series contains only ultra violate waves.