question_answer

Positronium consists of an electron and a positron (a particle which has the same mass as an electron, but opposite charge) orbiting round their common centre of mass. Calculate the value of the Rydberg constant for this system.          

A)                 \[{{R}_{\infty }}/4\]        

B)                 \[{{R}_{\infty }}/2\]

C)                 \[2{{R}_{\infty }}\]          

D)                 \[{{R}_{\infty }}\]