ອົງປະກອບຂອງໂລກທີ່ຫາຍາກປະກອບມີ lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (E), thulium (Tm), ytterbium (Yb), lutetium (Lu), scandium (Sc), ແລະ yttrium (Y). ອັງ...
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