One considers the coupling of the orbital angular momenta of two p electrons. a) From the tables of the Clebsh-Gordan coefficients, give the explicit form of the following states: |L M> = |2 2>, 12 1>, |2 0>, |1 1>, |1 -1> et 0 0>. b) What can you say about the symmetry properties of the obtained states with respect to the exchange of the two electrons?