←Tc   Fe↑   ↓Os   Rh→

Ruthenium ∙ ruthénium ∙ rutenio ∙ rutenio
group ‘n+n’ / noble gases and (rather) noble metals: R, RO₄

• melting point: 2334°C
• boiling point: 4150°C
• density: 12.2 g/cm³

Rutheniumtetroxid … gelber, leichtflüchtiger Feststoff … maximale Oxidationsstufe +8 … neben Osmiumtetroxid, Xenon(VIII)-oxid die einzige bekannte Verbindung [mit +8] … — Wikipedia

Ru-106 was released during the 1993 Tomsk accident … — IAEA

☢ radioisotopes:
Ru-106 (T1/2=371 d) fission product
Ru-103 (T1/2=39.3 d) fission product

… as well as in an October 2017 event in the Mayak region. — Science