Explanatory notes
… metals of heading 28.05 (lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, … . Ceric oxide, a white powder insoluble in water, is obtained from cerium nitrate; it is used as an opacifier in … are used in nuclear reactors for the absorption of slow neutrons. This heading excludes : (a) Natural compounds …