found: Encyc. Britannica online, Aug. 31, 2012(xenon (Xe), chemical element, a heavy and extremely rare gas of Group 18 (noble gases) of the periodic table. It was the first noble gas found to form true chemical compounds.)
found: Wikipedia, Aug. 31, 2012(Xenon is a chemical element with the symbol Xe and atomic number 54. It is a colorless, heavy, odorless noble gas, that occurs in the Earth's atmosphere in trace amounts.)
found: The element xenon, via It's elemental website, Aug. 31, 2012(Xenon; Xe; Phase at Room Temperature: Gas; Element Classification: Non-metal; Period Number: 5; Group Number: 18; Group Name: Noble Gas)