SPECTRA OF ALKLI ELEMENT, SPIN ORBIT INTERACTION & FINE STRUCTER OF ALKLI SPECTRA

SPECTRA OF ALKLI ELEMENT, SPIN ORBIT INTERACTION & FINE STRUCTER OF ALKLI SPECTRA

1. ASSIGNMENT ON SPECTRA OF ALKLI ELEMENT, SPIN ORBIT INTERACTION & FINE STRUCTER OF ALKLI SPECTRA

2. SPECTRA OF ALKLI ELEMENT

3. ALKALI METAL The  alkali metals  are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na ), potassium  (K ),  rubidium (Rb), caesium (Cs )   and  francium ( Fr) The alkali metals have very similar properties: they are all shiny, soft, highly reactive metals at standard temperature and pressure All the alkali metals react with water, with the heavier alkali metals reacting more vigorously than the lighter ones.

4. SPIN ORBIT INTERACTION THE   spin–orbit interaction  (also called  spin–orbit effect  or  spin–orbit coupling ) is an interaction of a particle's spin  with its motion. The first and best known example of this is that spin–orbit interaction causes shifts in an  electron's  atomic energy levels due to electromagnetic interaction between the electron's spin and the magnetic field generated by the electron's orbit around the nucleus .

5. Spectra of alkali atom

6. Spin-orbit coupling (I) An electron revolving about a nucleus finds itself in a magnetic field produced by the nucleus which is circling about it in its own frame of reference. This magnetic field then acts upon the electron’s own spin magnetic moment to produce substates in terms of energy. S=1/2 could make some single state (n,l,m) split into two substates.

7. Spin-orbit coupling (II) The coupling of two magnetic moments in an atom leads to an addition of the two angular momenta to yield a total angular momentum . j= l+s The total angular momentum has the magnitude of with j =|l ± 1/2| for a single electron system. The quantum number j is the quantum number of the total angular momentum . For a p electron, l =1, s =1/2, there are two states with j=1/2, 3/2, respectively.

8. Fine structure All energy levels except the s states of one-electron atoms are spit into two substates. This produces a doublet or multiplet structure of the spectral lines, namely, fine structure. It can not be explained by Coulomb interaction between the nucleus and the electrons. It results from a magnetic interaction between the orbital magnetic moment and spin magnetic moment of the electron, called spin-orbit coupling .

9. THANK YOU

10. Made By: Anita Malviya