Density oxygen family elements

Neutral extracting agents possessing oxygen-donor atoms (hard bases) in their structure easily coordinate trivalent lanthanide and actinide cations, but do not discriminate between the two families of elements, because the ion-dipole (or ion-induced dipole type) interactions mostly rely on the charge densities of the electron donor and acceptor atoms. As a result, the similar cation radii of some An(III) and Ln(III) and the constriction of the cation radius along the two series of /elements make An(III)/Ln(III) separation essentially impossible from nitric acid media. They can be separated, however, if soft-donor anions, such as thiocyanates, SCN-, are introduced in the feed (34, 35, 39, 77). 

Xenon, Xe, is a gaseous, nonmetallic element from family eight. It is a colorless, odorless gas or liquid. It is nonflammable and nontoxic at standard temperatnres and pressnres, but is an asphyxiant and will displace oxygen in the air. The boiling point is -162°F, and the vapor density is 05.987, which is heavier than air. Xenon is chemically unreactive however, it is not completely inert. The fonr-digit UN identification number is 2036 for the compressed gas and 2591 for the cryogenic liqnid. Xenon is used in luminescent tubes, flash lamps in photography, lasers, and as an anesthesia. 

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