Atomic Structure

CALCULATION OF WAVE NUMBER OF SPECTRAL LINES:
It has been observed that as we proceed from Lyman series to pfund series, the wave number of spectral lines decreases.
When on excited electron jumps from higher energy level to lower energy level, the energy emitted will form different spectral emission lines These can only be seen in the visible region called as Balmer series.
When electron jumps from   ,  and orbitals to  orbital , the energy released will be in the visible region, as shown in the figure:

The wave number  can be calculated for each jump as under

Put values in the above equation

= 2 then

DEFECTS IN BOHR’S ATOMIC MODEL:-

            Bohr’s atomic successfully explains.

( ,, )
            Bohr failed to explain the following
.

When the spectrum of hydrogen atom is taken in the magnetic field, and new lines are created (Zee man Effect). Similarly lines splits up in the electrical field called stark effect. This cannot be explained by Bohr’s theory.