Assertion: cobalt | /r/HasAspect | an oxidation number of +3
Facets:
Source sentences:
text: 3-) has an oxidation number of -3, so Co must have an oxidation number of +3.
text: The cobalt in the formula given has an oxidation number of +3, so that the total charge of the two cobalt ions will balance the total charge of the 3 oxide ions, which have an oxidation number of -2 each.