question_answer 35)

                    Positronium is just like a H-atom with the proton replaced by the positively charged anti-particle of the electron (called the positron which is as massive as the electron). What would be the ground state energy of positronium?

Answer:

                                     In Bohr's formula, m is called the reduced mass. In case of hydrogen atom, m = me = mass of electron. For positronium : electron revolves around a positron, both of mass me. Therefore, reduced mass                                                                      This is the ground state energy of positronium.