(一)什么叫稀土稀土是指元素周期表中原子序数从57(镧)—71(镥)的镧系元素,以及与镧系元素在化学性质上十分近似的钪与钇,共十七个元素,通常总称“稀土”元素。“稀土”这个名称是十八世纪的化学家们起的。当时以为这些东西在地球上很稀少,加之它们的氧化物与当时被称为“土”的碱金属(钙、锶、钡三元素)的氧化物很相似,所以就起了“稀土”这个名字。其实稀土元素并不 (A) what is rare earth rare earth refers to the periodic table in the atomic number of 57 (lanthanum) -71 (镥) lanthanide and lanthanide and the chemical properties are very similar to scandium and yttrium, a total of seventeen Elements, usually referred to as “rare earth” elements. The name “rare earth” is from the eighteenth century chemists. At that time they thought that these things were very rare on earth, and their oxides were very similar to the oxides of the alkali metals (calcium, strontium and barium, three elements) then known as “earth”, so they played the name “rare earth” . In fact, rare earth elements are not