P3O1S1I1T1R1O1N1I1U1M3
15 points
POSITRONIUM is validvalid
[n POSITRONIUMS]
a positron and and an electron bound together in a short-lived unit, similar to a hydrogen atom [n -S]
[n POSITRONIUMS]
a positron and and an electron bound together in a short-lived unit, similar to a hydrogen atom [n -S]