Neodymium general properties

PmCl3.xH20, Pm(N03)3.xH20, and Pm(C2O4)3.10H2O. It would be expected that promethium would form some stable compounds in the +2 oxidation state, though they are unlikely to be made in aqueous solution. No definite evidence has yet been obtained, since studies have been hindered both by the small quantities of the element available and by its radioactivity. The properties of promethium fit neatly into position between neodymium and samarium it is a microcosm of lanthanide chemistry in general. 

Osmium is of great interest to mantle geochemists because, in contrast with the geochemical properties of strontium, neodymium, hafnium, and lead, all of which are incompatible elements, osmium is a compatible element in most mantle melting processes, so that it generally remains in the mantle, whereas the much more incompatible rhenium is extracted and enriched in the melt and ultimately in the crust. This system therefore provides information that is different from, and complementary to, what we can learn from... 

For the two common lanthanides lanthanum and neodymium that there are no quality heat capacity measurements available between 20 and 298 K and the selected entropy values at 298 K are therefore little more than educated guesses. Further measurements are also required on alpha cerium between 20 and 96 K in order to obtain a precision value for the entropy at 298 K. What is woiryingly being shown up by these reviews is that for many of these elements, selected values in a particular region are generally based on only one set of measurements since other measurements differ so significantly that they cannot be considered. It is possible that measurements on the pure metals will become fewer and fewer as there is a concentration oti commercially exploiting the many extraordinary properties of lanthanide compounds. 

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