 The chemical behavior of ytterbium is similar to that of the rest of the lanthanides . Most ytterbium compounds are found in the + 3 oxidation state and its salts in this oxidation state are nearly colorless . Like europium , samarium , and thulium , the trihalides of ytterbium can be reduced to the dihalides by hydrogen , zinc dust , or by the addition of metallic ytterbium . The + 2 oxidation state only occurs in solid compounds and reacts in some ways similarly to the alkaline earth metal compounds ; for example , ytterbium ( II ) oxide ( <unk> ) shows the same structure as calcium oxide ( CaO ) . 
