[单选题]
According to the select ea0(vl)hv1m3p u3oz tion rule, when a photon is emitt (c; khhk5tycj9v5:hued or absorbed, transitions can only occur between state with values of l that;jcht ku(9hc5k5:vh y differ by
A. four units.
B. three units.
C. two units.
D. one unit.
Post time 2024-1-22 00:52:27