Trinket. Chlorine.

<div>   </div> <div> <strong> Atomic number <span class = "Apple-tab-span" style = "white-space: pre;"> </span>     17 </strong> </div> <div> <strong> Atomic mass     <span class = "Apple-tab-span" style = "white-space: pre;"> </span> 35,453 </strong></div> <div> <strong> Density, kg / m?   <span class = "Apple-tab-span" style = "white-space: pre;"> </span> 0.317 < / strong> </div> <div> <strong> Temperature </strong></div> <div> <strong> melting, ° С       <span class = "Apple-tab-span" style = "white-space: pre;"> </span>-101</strong></div> <div>   </div> < div> Chlorine is a poisonous gas of yellowish-green color, heavier than air, with a pungent odor and sweetish, "metallic" taste. Chlorine was obtained for the first time in 1774 by K. Scheele by the interaction of hydrochloric acid with pyrolusite. However, only in 1810 G. Davy established that chlorine is an element and named it chlorine (from the Greek chloros - yellow-green). In 1813, J.L. Gay-Lussac proposed the name Chlorine for this element. </div> <div> Chlorine is the most abundant halogen in the earth's crust. Chlorine is very active - it combines directly with almost all elements of the periodic table. Therefore, in nature, it is found only in the form of compounds in the composition of minerals. </div>