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稀土金属是周期表中ⅢB组原子序数从57到71的十五种性质近似的金属元素。根据它们的性质,可以分为铈组(镧La、铈Ce、镨Pr、钕Nd、钷Pm、钐Sm、铕Eu)和钇组(钆Gd、铽Tb、镝Dy、钬Ho、铒Er、铥Tm、镱Yb、镥Lu)。原子序数21的钪Sc和39的钇Y,也常包括在钇组中。所以稀土金属共有十七种金属元素。事实上,稀土金属并不是“稀”,根据现在所知道的,地壳中的含量有0.0159%,比铅、锌、锡和贵金属等要多几十倍到几百倍。稀土金属也不是“土”。从前人
The rare earth metals are fifteen metallic elements of approximate nature from 57 to 71 in Group IIIB of the Periodic Table. According to their properties, they can be classified into cerium group (La, Ce, Pr, Nd, Pm, Sm, Eu) , 铥 Tm, ytterbium Yb, 镥 Lu). Sc Sc Sc of atomic number 21 and yttrium Y of 39 are also often included in the yttrium group. Therefore, a total of seventeen rare earth metals metal elements. In fact, rare earth metals are not “lean,” and as far as we know, there are 0.0159% of the earth’s crust, several tens to hundreds of times more than lead, zinc, tin and precious metals. Rare earth metal is not “earth.” From the previous person