Classification of rare earths

1) Light rare earth (also known as 铈 group): 镧 , 铈, 镨 , 钕 , 钷, 钐 , 铕 , 钆 .

2) Heavy rare earth (also known as 钇 group): 铽 , 镝 , 钬 , 铒 , 铥 , 镱 , 镥 , 钪 , 钇.

The difference between the 铈 group and the 钇 group is because the rare earth mixture obtained by separation of minerals is often named after the ratio of lanthanum or cerium.

Rare earth metals (rare earth metals), also known as a rare earth element, is a general term for a group ⅢB periodic table scandium, yttrium, lanthanides 17 elements, commonly represented by R or RE. Their names and chemical symbols are 钪 (Sc), 钇 (Y), 镧 (La), 铈 (Ce), 镨 (Pr), 钕 (Nd), 钷 (Pm), 钐 (Sm), 铕 (Eu ), Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. Their atomic numbers are 21 (Sc), 39 (Y), 57 (La) to 71 (Lu).

The element "La" "镧" was named in 1839, when a Swede named "Moussand" discovered that the earth contained other elements. He borrowed the word "hidden" in Greek to use this element. Named "镧".

The application of germanium is very extensive, such as piezoelectric materials, electrothermal materials, thermoelectric materials, magnetoresistive materials, luminescent materials (blue powder), hydrogen storage materials, optical glass, laser materials, various alloy materials, and the like. It is also used in the preparation of many organic chemical products. The light-transfer agricultural film is also used in the field. In foreign countries, scientists have given the role of cockroaches to crops as the name of “super calcium”.