 This route gives white europium ( III ) fluoride ( <unk> ) , yellow europium ( III ) chloride ( <unk> ) , gray europium ( III ) bromide ( <unk> ) , and colorless europium ( III ) iodide ( <unk> ) . Europium also forms the corresponding <unk> : yellow @-@ green europium ( II ) fluoride ( <unk> ) , colorless europium ( II ) chloride ( <unk> ) , colorless europium ( II ) bromide ( <unk> ) , and green europium ( II ) iodide ( <unk> ) . 
