M3U1O1N1I1U1M3S1
12 points
MUONIUMS is validvalid
MUONIUM, an electron and a positive muon bound together [n]
MUONIUM, an electron and a positive muon bound together [n]
MUONIUM, an electron and a positive muon bound together [n]
MUONIUM, an electron and a positive muon bound together [n]