What is ionization energy of positronium?

Question

Positronium is hydrogen-like atom in which
proton is replaced with positron.

Ionization energy of hydrogen is 13.6eV.

Answer 1

The positronium atom is similar to a hydrogen atom except that the reduced mass m1*m2/(m1+m2) applying to the wave equation of the relative coordinate is half the electron mass instead of the full electron mass. That causes the Bohr radius to be expanded by a factor of 2 and scales down the energy of each state by a factor of 2 --> the ionization energy for the ground state is 6.8 ev.

This is a nonrelativistic approximation like the usual treatment of the hydrogen atom.

Answer 2

Positronium (Ps) is a system consisting of an electron and its anti-particle, a positron, bound together into an "exotic atom".

Positronium is unstable, with a lifetime of at most 143ns nanoseconds in its orthogonal ground state, note however that positronium in the 2S state is metastable having a lifetime of 1.1 μs against annihilation.

As such, I don't think activation energy applies.

Answer 3

A positron is an anti electron. Positronium was a star trek creation. If you could build and atom out of antimatter which we have it will be the same as normal matter.