Question

.019 1. When Johann Balmer found his famous series for hydrogen in wavelengths in the visible and near ultraviolet regions from series lie in that region. On the basis of the entries in Table 11.3 and me diagram, what common characteristic do the lines in the Balmer sein Print Preview ous series for hydrogen in 1886, he was limited experimentally to car ultraviolet regions from 250 nm to 700 nm, so all the lines in his entries in Table 11.3 and the transitions on your energy level What would be the longest possible wavelength for a line in the Balmer series nm What would be the shortest possible wavelength that a line in the Balmer series could have? (Hint: What is the largest possible value of AE that can be associated with a line in the Balmer series?) nm Fundamentally, why would any line in the hydrogen spectrum between 250 nm and 700 nm belong to the Balmer series? (Hint: On the energy level diagram note the range of possible values of AE for transitions to the n = I level and to the = 3 level. Could a spectral line involving a transition to the n = 1 level have a wavelength in the range indicated?)

Answer 1

1) longest possible wavelength associated transition.it is having lowest energy in the series.

so that, in balmer series lowest possible energy transition is between 2 and 3 levels

wavenumber = 1/wavelength = 109677(1/n1^2-1/n2^2) cm-1

     n1 = 2 , n2 = 3

   1/wavelength = 109677(1/2^2-1/3^2)

            1/l = 15233 cm-1

        l = wavelength = 1/15233 = 6.56*10^-5 cm

   wavelength = 6.56*10^-5*10^7 = 656 nm

2) shortest wavelength associated transition.it is having highest energy in the series.

so that, in balmer series highest possible energy transition is between 2 and infinity levels

wavenumber = 1/wavelength = 109677(1/n1^2-1/n2^2) cm-1

     n1 = 2 , n2 = infinity

   1/wavelength = 109677(1/2^2-1/(infinity)^2)

            1/l = 27419.25 cm-1

        l = wavelength = 1/27419.25 = 3.65*10^-5 cm

   wavelength = 3.65*10^-5*10^7 = 365 nm

Balmer series lines are present in visible region.so that its wavelengths are in the range of 365 to 656 nm.