Keychain. Neodymium.

<div>   </div> <div> <strong> Atomic number <span class = "Apple-tab-span" style = "white-space: pre;"> </span>       60 </strong> </div> <div> <strong> Atomic mass       <span class = "Apple-tab-span" style = "white-space: pre;"> </span>144,24</strong></div> <div> <strong> Density, kg / m ? <span class = "Apple-tab-span" style = "white-space: pre;"> </span>     7000 </strong> </div> <div> <strong> Temperature</strong></div> <div> <strong> melting, ° С <span class = "Apple-tab-span" style = "white- space: pre; "> </span>         1024 </strong> </div> <div>   </div> <div> Neodymium is a rare earth metal with a silvery white color with a golden hue. Oxidizes easily in air. Neodymium was discovered in 1885 by the Austrian chemist Karl Auer von Welsbach. He divided didyme - a mixture of two rare earth metals, difficult to separate due to the extreme closeness of their chemical properties and previously considered an individual chemical element - into neodymium and praseodymium. It was possible to obtain neodymium in its pure form, practically free from impurities of praseodymium, only in 1925. </div> <div>   </div>