Keychain Lr Lawrencium.

<div> <strong> Atomic number <span class = "Apple-tab-span" style = "white-space: pre;"> </span>       103 </strong> </div> <div> <strong> Atomic mass         <span class = "Apple-tab-span" style = "white-space: pre;"> </span>260</strong></div> <div> <strong> Density, kg / m ? <span class = "Apple-tab-span" style = "white-space: pre;"> </span>           -   </strong> </div> <div> <strong> Temperature</strong></div> <div> <strong> Melting, ° С           1627 </strong> </div> <div>   </div> <div>   </div> <p> Lawrence is a radioactive metal. Element 103 was obtained in the USSR at the accelerator at the Joint Institute for Nuclear Research (science city Dubna) in 1961 - 1965 by G. N. Flerov's group and independently at the N.N. Lawrence at Berkeley (USA, February 14, 1961). The Soviet achievement in the USSR was recognized as a scientific discovery and entered into the State Register of Discoveries of the USSR under No. 132. </p>