Search results
Results from the WOW.Com Content Network
Thus, despite its position as one of the so-called rare-earth metals, cerium is actually not rare at all. [46] Cerium content in the soil varies between 2 and 150 ppm, with an average of 50 ppm; seawater contains 1.5 parts per trillion of cerium. [38] Cerium occurs in various minerals, but the most important commercial sources are the minerals ...
The γ polymorph of cerium(III) sulfide adopts a cation-deficient form of the Th 3 P 4 structure. 8 out the 9 metal positions in the Th 3 P 4 structure are occupied by cerium in γ-Ce 2 S 3, with the remainder as vacancies. This composition can be represented by the formula Ce 2.667 0.333 S 4.
The rare-earth elements (REE), also called the rare-earth metals or rare earths, and sometimes the lanthanides or lanthanoids (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), [1] are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds containing rare ...
Some of the bastnäsites contain OH − instead of F − and receive the name of hydroxylbastnasite. Most bastnäsite is bastnäsite-(Ce), and cerium is by far the most common of the rare earths in this class of minerals. Bastnäsite and the phosphate mineral monazite are the two largest sources of cerium and other rare-earth elements.
The rare earth element neodymium is found in monazite, making it a rare mineral. [25] Moreover, monazite contains many other rare metals such as cerium, lanthanum, praseodymium, and samarium, making it a critical source of renewable energy. [26] Recycled magnets can also be derived from these minerals due to the metals they contain. [25]
Samarium dissolves readily in dilute sulfuric acid to form solutions containing the yellow [22] to pale green Sm(III) ions, which exist as [Sm(OH 2) 9] 3+ complexes: [21] 2Sm (s) + 3H 2 SO 4 (aq) → 2Sm 3+ (aq) + 3SO 2− 4 (aq) + 3H 2 (g) Samarium is one of the few lanthanides with a relatively accessible +2 oxidation state, alongside Eu and ...
Cerium(III) sulfate is one of the few salts whose solubility in water decreases with rising temperature. [12] Ceric ammonium nitrate. Due to ligand-to-metal charge transfer, aqueous cerium(IV) ions are orange-yellow. [13] Aqueous cerium(IV) is metastable in water [14] and is a strong oxidizing agent that oxidizes hydrochloric acid to give ...
Samarium is one of the few lanthanides that form a monoxide, SmO. This lustrous golden-yellow compound was obtained by reducing Sm 2 O 3 with samarium metal at high temperature (1000 °C) and pressure above 50 kbar; lowering the pressure resulted in incomplete reaction. SmO has cubic rock-salt lattice structure.