 Xenon is a chemical element with symbol Xe and atomic number 54 . It is a colorless , dense , odorless noble gas , that occurs in the Earth 's atmosphere in trace amounts . Although generally unreactive , xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate , the first noble gas compound to be synthesized . 
 Xenon <a href='drop_aux' title='1'><mark>is</mark></a>a chemical element with symbol Xe and atomic number 54 . It is a colorless , dense , odorless noble gas , that <a href='uninflect' title='2'><mark>occurs</mark></a> in the Earth <a href='null_genetive' title='3'><mark>'s</mark></a>atmosphere in trace amounts . Although generally unreactive , xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate , the first noble gas compound to be synthesized . 
Xenon a chemical element with symbol Xe and atomic number 54 . It is a colorless , dense , odorless noble gas , that occur in da Earth  atmosphere in trace amounts . Although generally unreactive , xenon can undergo a few chemical reactions such as the formation of xenon hexafluoroplatinate , the first noble gas compound to be synthesized .