Treat He ( ) as a hydrogenic ion with its reduced mass taken equal to
PHYSICS · Multi-part · Fermi University Physics · Atomic, Molecular & Optical Physics · One-electron atoms and the origins of atomic structure · One-electron atoms and the origins of atomic structure
Deriving the Spectrum, Ch The exact Coulomb problem and Rydberg states
Problem
Treat He+ (Z=2) as a hydrogenic ion with its reduced mass taken equal to me, so that En=−Z2(13.6057eV)/n2. Take α=1/137.036 and e2/(4πϵ0a0)=27.2114eV.
((a)) For n=3, use the virial theorem to split E3 into ⟨T^⟩ and ⟨V⟩, in eV.
((b)) Check ⟨V⟩ independently from the radial moment ⟨r−1⟩.
((c)) Find the root-mean-square speed of the electron as a fraction of c, and compare it with the speed in hydrogen's n=3 level.