Question

Which series of hydrogen spectrum is in the violet region?
[A] Lyman series
[B] Balmer series
[C] Paschen series
[D] Brackett series

Answer 1

In order to solve this question we need to understand the hydrogen spectrum. So at quantum level energy levels are discrete so at low temperature all electrons prefer to be in ground state but when it absorb photon or energy it gets excited to a new higher level suppose it excited to first energy level then it stays there for very less duration of time ${10^{ - 8}}\sec$ and then it falls back to ground state and hence releasing a photon having same energy as energy difference between energy level which is mathematically defined as, $hv = {E_2} - {E_1}$ here $v$ is frequency, so a hydrogen atom when kept in a light it emits different frequency due to transitions from higher excited level to lower energy level, this different range of frequency is known as spectrum.

Complete step-by-step solution:
Different transitions are named on basis of scientist who discover these transitions like
When the transitions occurs from any higher excited state to ground state or first orbit of electron around nucleus then the transitions are known as Lyman series
Similarly, when the transitions occurs from any higher excited state to second orbit of electron around nucleus then the transitions are known as Balmer series
Similarly, when the transitions occurs from any higher excited state to third orbit of electron around nucleus then the transitions are known as Paschen series
Similarly, when the transitions occurs from any higher excited state to fourth orbit of electron around nucleus then the transitions are known as Brackett series
Since, the wavelength of violet light is close to $380nm$ and Balmer series is one which comprise of visible light region which has a range of close to $400nm - 700nm$ and since violet light is also falls in visible lights category so, violet regions comes under Balmer series.
So the correct option is, [B] Balmer series.

Note: It should be remembered that Lyman series corresponds to least wavelength hence UV rays falls in this region while in Paschen series, spectral lines corresponds to near Infrared region and in Brackett series, spectral lines corresponds to Infrared radiations. These spectral lines are very important in astronomy as it gives so much information about deep space, galaxies etc.