assertion  retraction  graph  subject          predicate        object           datatype    annotation
1          0           graph  obo:CHEBI_28073  rdfs:label       chromium atom    xsd:string  
1          0           graph  obo:CHEBI_28073  oio:id           CHEBI:28073      xsd:string  
1          0           graph  obo:CHEBI_28073  rdfs:subClassOf  obo:CHEBI_88184  _IRI        
1          0           graph  obo:CHEBI_28073  rdfs:subClassOf  obo:CHEBI_33350  _IRI        
1          0           graph  obo:CHEBI_28073  rdf:type         owl:Class        _IRI