Praseodymium nature only one stable isotope, 141-Pr. However, there are 38 radioisotopes, of which 143-Pr is relatively stable with a half-life of 13.57 days and 142-Pr with a half-life of 19.12 hours. Other radioisotopes have a half-life of more than 5.985 hours, with most half-lives less than 33 seconds. There are also six metastable states. The more stable ones are 138m-Pr (t1â„2; 2.12 hours), 142m-Pr (t1â„2: 14.6 minutes) and 134m-Pr (t1â„2: 11 points). The atomic weight of strontium is from 120.955 u (121-Pr) to 158.955 u (159-Pr). The stable isotope 141-Pr captures electrons if it emits beta rays. The main product is radiation isotopes of cerium Ce and Nd 58 Nd 60 isotope. It has two crystals: α hexagonal crystal, melting point of 931 ° C, boiling point of 3512 ° C, density of 6.77 g / cm 3 ; β cubic crystal, melting point of 935 ° C, boiling point of 3127 ° C, density of 6.64 g / cm 3 . External electron shell arrangement 4f36s2, gray metallic silver. A lively metal that reacts with water to release hydrogen. Wet air oxidation, an oxide layer formed on the surface, therefore, is often stored in a sealed container filled with coal oil. Source of elements: mainly in monazite. It is usually obtained by dehydration of hydrated lanthanum chloride PrCl 3 ·XH 2 O with metal calcium or by electrolysis of anhydrous cerium chloride after melting. Elements of supporting information: After self Mosangdeer has found that lanthanum, erbium and terbium, pay particular attention to countries chemists to separate new elements from rare earth elements have been found. In the same period found that the separation of samarium and gadolinium, the 1885 Austrian chemist韦尔塞巴赫from didymium (at that time was considered a rare earth element) oxide in the oxide two new elements, one of which is named For preseodidymium, it was later simplified to praseodymium, the element symbol Pr. 镨, é’†, é’, é’• are separated from the didymium which was considered to be a rare earth element at the time. Due to their discovery, didymium is no longer reserved. And it is their discovery that opened the third door to the discovery of rare earth elements and the third stage of discovering rare earth elements. But this is only half of the work done in the third phase. The exact will be open the door to complete the separation of cerium or cerium, yttrium and the other half will open the door or complete separation of yttrium. Magnetic Pump have the magnetic seal, pump no leakage, safety, stable operation. Widely used in chemical industry and food industry. we have Magnetic gear pump, Magnetic Centrifugal Pump, Magnetic screw pump and Magnetic rotor pump. base on all kind of pump's properties, pump be installed a magnetic coupling, the conveying medium has no leakage and the working environment is clean and tidy. No need to change the seal, easy to use and easy to operate. Depending on the medium being transported, the working environment is different and different pumps are selected. Magnetic Pump Magnetic Pump,Magnetic Gear Pumps,Magnetic Drive Water Pump,Magnetic Air Pump Botou Honghai Pump Co.,Ltd , http://www.pumphonghai.com
Antimony ore