GRE Physics GR 1777 Problem Solution

023. Quantum Mechanics (Positronium)

You should know about

• Rydberg constant for positronium may be calculated from the reduced mass

$latex R_M = R_\\infty \\Big( \\frac{M}{m_e + M} \\Big) = R_\\infty \\Big( 1 + \\frac{m_e}{M} \\Big)^{-1}$

Solution

Answer

(B) 0.5 $latex R_\\infty$

Reference

https://en.wikipedia.org/wiki/Positronium

https://en.wikipedia.org/wiki/Rydberg_constant