Trinket. Xenon.

<div>   </div> <div> <strong> Atomic number <span class = "Apple-tab-span" style = "white-space: pre;"> </span>     54 </strong> </div> <div> <strong> Atomic mass <span class = "Apple-tab-span" style = "white-space: pre;"> </span>       131.29 </strong> </div> <div> <strong> Density, kg / m?     <span class = "Apple-tab-span" style = "white-space: pre;"> </span>5,86</strong></div> <div> <strong> Temperature </strong> </div> <div> <strong> melting, ° С       <span class = "Apple-tab-span" style = "white-space: pre;"> </span>-111,9</strong></div> <div>   </div> <div> Xenon is a noble monoatomic gas without color, taste or odor. Discovered in 1898 by English researchers William Ramsay and Maurice Travers, who slowly evaporated liquid air and studied its most volatile fractions by spectroscopic method. Xenon was discovered as an impurity to krypton, which explains its name. Xenon is a very rare element. Xenon is used to fill incandescent lamps, high-power gas-discharge and pulsed light sources (the high atomic mass of the gas in the lamp bulbs prevents the evaporation of tungsten from the filament surface). </div> <div>   </div>