 4 ) , both of which are dangerously explosive and powerful oxidizing agents , and xenon dioxide ( XeO2 ) , which was reported in 2011 with a coordination number of four . XeO2 forms when xenon tetrafluoride is poured over ice . Its crystal structure may allow it to replace silicon in silicate minerals . The XeOO + cation has been identified by infrared spectroscopy in solid argon . 
 4 ) , both of which <a href='drop_aux' title='1'><mark>are</mark></a>dangerously explosive and powerful oxidizing agents , and xenon dioxide ( XeO2 ) , which was reported in 2011 with a coordination number of four . XeO2 forms when xenon tetrafluoride is poured over ice . Its crystal structure may allow it to replace silicon in silicate minerals . The XeOO + cation <a href='been_done' title='2'><mark>has</mark></a> been identified by infrared spectroscopy in solid argon . 
4 ) , both of which dangerously explosive and powerful oxidizing agents , and xenon dioxide ( XeO2 ) , which was reported in 2011 witt a coordination number of four . XeO2 forms when xenon tetrafluoride is poured ova ice . Its crystal structure may allow it to replace silicon in silicate minerals . The XeOO + cation done been identified by infrared spectroscopy in solid argon .