Брелок с люминофором. Технеций (Tc). Не содержит элемента!

<div>   </div> <div> <strong> Atomic number   <span class = "Apple-tab-span" style = "white-space: pre;"> </span> 43 </strong> </div> <div> <strong> Atomic mass <span class = "Apple-tab-span" style = "white-space: pre;"> </span>     98 </strong> </div> <div> <strong> Density, kg / m? & Nbsp; <span class = "Apple-tab-span" style = "white-space: pre;"> </span> & nbsp ; 11500 </strong> </div> <div> <strong> Temperature </strong></div> <div> <strong> melting, ° С <span class = "Apple-tab-span" style = "white -space: pre; "> </span>       2140 </strong> </div> <div>   </div> <div> Technetium is a silver-gray radioactive transition metal. The existence of an element with atomic number 43 was predicted by D.I.Mendeleev. Technetium was obtained artificially in 1937 by the Italian scientists E. Segre and C. Perrier during the bombardment of molybdenum nuclei with deuterons; got its name from the Greek. technetos is artificial. Technetium has no stable isotopes. Technetium is a promising metal in technology; it can find application as a catalyst, high temperature and superconducting material. Technetium compounds are effective corrosion inhibitors. Technetium is used in medicine as a source of γ-radiation. Technetium is radiation hazardous, working with it requires special sealed equipment. </div> <div>   </div>