How Can Noble Gases Form Compounds

Ever since their discovery in the late 19 century, these elements were considered, and in fact, were generally referred to as, the inert gases. Atomic theory and, more important, all experiments had supported this idea. Then, in 1962, all this changed when the first noble gas compound was prepared. 

Atomic mass Valence e configuration Common oxidation states 

Grou ) electron configuration is for He and ns np for the others. The valence shell is filled. Only Kr and Xe (and perhaps Rn) are known to form compounds. The more reactive Xe exhibits all even oxidation states (+2 to + 8). This group contains the smallest atoms with the highest lEs in their periods. Down the group, atomic size increases and IE decreases steadily. (EN values are given only for Kr and Xe.) 

Melting and boiling points of these gaseous elements are extremely low but increase down the group because of stronger dispersion forces. Note the extremely small liquid ranges. Densities (at STP) increase steadily, as expected. 

02 (1175 kJ/mol) is very close to IE) of xenon (1170 kJ/mol), Bartlett reasoned that PtFe could oxidize xenon. He prepared XePtFg, an orange-yellow solid, and within a few months, XeFa and Xep4 were also prepared. In addition to its +2 and -t-4 oxidation states, Xe has the -f 6 state in several compounds, such as XeFe and Xe03, and the +8 state in the unstable oxide, Xe04. A few compounds of Kr and Rn have also been made. 

For Review and Reference (Numbers in parentheses refer to pages, unless noted otherwise.) 

Discuss key features of Group 5A(I5), especially patterns in oxidation state, oxide acidity, and hydride and halide structures and describe the nitrogen and phosphorus oxides and oxoacids ( 14.6) (EPs 14.48-14.58) 

---