Keychain. Cerium.

<div>   </div> <div> <strong> Atomic number     <span class = "Apple-tab-span" style = "white-space: pre;"> </span>58</strong></div> <div> <strong> Atomic mass <span class = " Apple-tab-span "style =" white-space: pre; "> </span>     140,12 </strong> </div> <div> <strong> Density, kg / m? <Span class = "Apple-tab-span" style = "white-space: pre;"> </span> & nbsp ; 6770 </strong> </div> <div> <strong> Temperature </strong></div> <div> <strong> melting, ° С <span class = "Apple-tab-span" style = "white- space: pre; "> </span>       795 </strong> </div> <div>   </div> <div> Cerium is a chemical element from the lanthanide group, a silvery metal. Named after the largest of the minor planets, Ceres, in turn named after the Roman goddess of fertility. </div> <div> German chemist M.G. Klaproth, who discovered the land of cerium almost simultaneously with his Swedish colleagues B Hisinger and J. Ya. Berzelius, objected to the name "cerium", proposing "cerium". Berzelius, however, defended his name, citing the difficulty of pronouncing the name that Klaproth proposed to the new element. </div> <div> The main deposits of cerium are located in the USA, Kazakhstan, Russia, Ukraine, Australia, Brazil, India, Scandinavia. < / div> <div>   </div>