naming a element

Question

what is the name of Cr(little 2)O(little 3)

Answer 1

Cr is chromium, a transition metal

O is oxygen, a nonmetal

 

Metals (cation) + nonmetals (anion) are named as "cation anide." That is, the cation and anion but the anion's ending gets dropped and you add "-ide."

 

We would expect Cr₂O₃ to be named Chromium Oxide, but there is one more rule. Transition metals are metals that have different common oxidation states. This chromium has an oxidation state of +3, which means the name of this compound is actually Chromium (III) Oxide.

Answer 2

Cr₂O₃ is Chromium Oxide