 Because of the high reactivity , samples of solid europium rarely have the shiny appearance of the fresh metal , even when coated with a protective layer of mineral oil . Europium ignites in air at 150 to 180 ° C to form europium ( III ) oxide : 
 Because of the high reactivity , samples of solid europium rarely <a href='got' title='1'><mark>have</mark></a> the shiny appearance of the fresh metal , even when coated with a protective layer of mineral oil . Europium ignites in air at 150 to 180 ° C to form europium ( III ) oxide : 
Because of the high reactivity , samples of solid europium rarely got da shiny appearance of the fresh metal , even when coated w/ a protective layer of mineral oil . Europium ignites in air at 150 to 180 ° C to form europium ( III ) oxide :