| |
- It is observed in the sodium spectrum (shown in the figure below) that D-line (yellow emission) is split into two lines
D1 = 5895.93 Å or 589.59 nm, D2 = 5889.9 Å or 588.99 nm
- The reason of observing this doublet is that the energy levels split into two for the terms except s-level (l = 0).
- Many lines of the other alkali atoms are also doublets.
- With high resolution spectrometer shows that even hydrogen atom lines are also having this doublet nature.
- The Coulomb interactions between the nucleus and electron in the outermost orbit for alkali atoms can not explain this observation
- Not only alkali atoms, but also in the other multielectron atoms the transitions between the terms split into more number of transitions. This is known as Fine structure.
|
|
|
|
|
