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                              1. ▸▸
                                • 🇬🇧 Promethium
                                • 🇨🇳 鉕
                                • 🇳🇱 Promethium
                                • 🇫🇷 Prométhium
                                • 🇩🇪 Promethium
                                • 🇮🇱 פרומתיום
                                • 🇮🇹 Prometio
                                • 🇯🇵 プロメチウム
                                • 🇵🇹 Promécio
                                • 🇷🇺 Прометий
                                • 🇪🇸 Prometio
                                • 🇸🇪 Prometium

                                Promethium: the essentials

                                Promethium atoms have 61 electrons and the shell structure is 2.8.18.23.8.2. The ground state electronic configuration of neutral promethium is [Xe].4f5.6s2 and the term symbol of promethium is 6H5/2.

                                Promethium: description  

                                网络斗地主下载Great care is required while handling promethium as a consequence of its radioactivity. Promethium salts luminesce in the dark with a pale blue or greenish glow, due to their high radioactivity. Ion-exchange methods led to the preparation of about 10 g of promethium from atomic reactor fuel processing wastes in early 1963.

                                Little is yet generally known about the properties of metallic promethium. More than 30 promethium compounds have been prepared. Promethium is a rare earth metal. It appears that there is no known Pm existing in the earth's crust.

                                promethium
                                网络斗地主下载This sample is from , an attractive and safely packaged collection of the 92 naturally occurring elements that is available for sale.

                                Promethium: physical properties

                                More physical properties...

                                Promethium: heat properties

                                More thermochemical properties...

                                Promethium: atom sizes

                                More atomc size properties...

                                Promethium: electronegativities

                                More electronegativity properties...

                                Promethium: orbital properties

                                More orbital properties...

                                Promethium: abundances

                                More geological data...

                                Promethium: crystal structure

                                Pm crystal structure
                                The solid state structure of promethium is: bcc (body-centred cubic).

                                More crystallographic data...

                                Promethium: biological data

                                Promethium has no biological role.

                                More biological data...

                                Promethium: uses

                                Uses...

                                Promethium: reactions

                                网络斗地主下载 Reactions of promethium as the element with air, water, halogens, acids, and bases where known.

                                View reactions of promethium...

                                Promethium: binary compounds

                                网络斗地主下载 Binary compounds with halogens (known as halides), oxygen (known as oxides), hydrogen (known as hydrides), and other compounds of promethium where known.

                                View binary compounds...

                                Promethium: compound properties

                                网络斗地主下载 Bond strengths; lattice energies of promethium halides, hydrides, oxides (where known); and reduction potentials where known.

                                View compound properties...

                                Promethium: history

                                Promethium was discovered by J. A. Marinsky, Lawrence Glendenin, Charles D. Coryell in 1945 at United States. Origin of name: named after "Prometheus" in Greek mythology, who stole fire from the gods.

                                More history...

                                Promethium: isotopes

                                Isotope abundances of promethium
                                Isotope abundances of promethium with the most intense signal set to 100%.

                                More isotope and NMR data...

                                Promethium: isolation

                                Isolation: promethium metal is available commercially so it is not normally necessary to make it in the laboratory, which is just as well as it is difficult to isolate as the pure metal. This is largely because of the way it is found in nature. The lanthanoids are found in nature in a number of minerals. The most important are xenotime, monazite, and bastnaesite. The first two are orthophosphate minerals LnPO4 (Ln deonotes a mixture of all the lanthanoids except promethium which is vanishingly rare) and the third is a fluoride carbonate LnCO3网络斗地主下载F. Lanthanoids with even atomic numbers are more common. The most comon lanthanoids in these minerals are, in order, cerium, lanthanum, neodymium, and praseodymium. Monazite also contains thorium and ytrrium which makes handling difficult since thorium and its decomposition products are radioactive.

                                For many purposes it is not particularly necessary to separate the metals, but if separation into individual metals is required, the process is complex. Initially, the metals are extracted as salts from the ores by extraction with sulphuric acid (H2SO4), hydrochloric acid (HCl), and sodium hydroxide (NaOH). Modern purification techniques for these lanthanoid salt mixtures are ingenious and involve selective complexation techniques, solvent extractions, and ion exchange chromatography.

                                Pure promethium is available through the reduction of PmF3网络斗地主下载 with calcium metal.

                                2PmF3 + 3Ca → 2Pm + 3CaF2

                                This would work for the other calcium halides as well but the product CaF2 is easier to handle under the reaction conditions (heat to 50°C above the melting point of the element in an argon atmosphere). Excess calcium is removed from the reaction mixture under vacuum.

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