transition element atom ruthenium atom 0 101.07000 101.904 44Ru CAS:7440-18-8 CHEBI:30682 InChI=1S/Ru KJTLSVCANCCWHF-UHFFFAOYSA-N Ru Ruthenium WebElements:Ru [Ru] chebi.owl chebi_ontology obi.owl rutenio ruthenium ruthenium iron group element atom