Atomic holmium

Heat of vaporization, 66 see also Vaporization Helium, 91 boiling point, 63 heat of vaporization, 105 interaction between atoms, 277 ionization energy, 268 molar volume, 60 on Sun, 447 source, 91 Hematite, 404 Hemin, structure of, 397 Hess s Law, 111 Heterogeneous, 70 systems and reaction rate, 126 n-Hexane properties, 341 Hibernation, 2 Hildebrand, Joel H.. 163 Holmium, properties, 412 Homogeneous, 70 systems and reaction rate, 126 Hydration, 313 Hydrazine, 46, 47, 231 Hydrides of third-row elements, 102 boiling point of. 315 Hydrocarbons, 340 unsaturated, 342... 

On the other hand, lanthanides with 100% isotopical purity such as terbium or holmium are preferred to simplify the operation and minimize decoherence in spin qubits. In this respect, the existence, for some lanthanides, of a manifold of electronuclear states can provide additional resources for the implementation of multiple qubit states within the same molecule [31]. All atoms in the first coordination sphere should be oxygen, and the sample should be deuter-ated if the compound contains hydrogen, to avoid interaction with other nuclei spins. Again, POM chemistry has been shown to provide ideal examples of this kind. 

Dysprosium - the atomic number is 66 and the chemical symbol is Dy. The name derives from the Greek dysprositos for hard to get at , due to the difficulty in separating this rare earth element from a holmium mineral in which it was found. Discovery was first claimed by the Swiss chemist Marc Delafontaine in the mineral samarskite in 1878 and he called it philippia. Philippia was subsequently found to be a mixture of terbium and erbium. Dysprosium was later discovered in a holmium sample by the French chemist Paul-Emile Lecoq de Boisbaudron in 1886, who was then credited with the discovery. It was first isolated by the French chemist George Urbain in 1906. 

Holmium - the atomic number is 67 and the chemical symbol is Ho. The name derives from the Latin holmia for Stockholm . It was discovered in erbia earth by the Swiss chemist J. L. Soret in 1878, who referred to it as element X. It was later independently discovered by the Swedish chemist Per Theodor Cleve in 1879. It was first isolated in 1911 by Holmberg, who proposed the name holmium either to recognize the discoverer Per Cleve, who was from Stockholm or perhaps to establish his own name in history. 

Cleve s fame rests chiefly, however, on his discoveries among the rare earths. After obtaining some erbia from which all the ytterbia and scandia had been removed, and after noticing that the atomic weight of the erbium was not constant, he succeeded in resolving the earth into three constituents erbia, holmia, and thulia (21). The absorption bands of holmium had already been noticed by the Swiss chemists M. Delafontaine... 

Johnson et al. (55) observed energy transfer from erbium to thulium and from erbium to holmium ions in crystals. They were able to obtain substantial decreases in laser thresholds because of this energy migration. The fluorescent lifetime of the 3//4 state of thulium in CaMo04 containing 0.75 atomic per cent erbium and 0.5 atomic per cent thulium as inferred from the time delay before the onset of laser oscillation is 900 /xsec at both IT and 20°K. 

Fig. 12.33 The molecular unit of tn s((lrphenylpro-paredionalo)aquahol-mium(lll) projected down the threefold axis. The water molecule is directly above the holmium atom but has been displaced slightly in this drawing to show the structure better. [From Zalkin, A. Templeton, O. H. Karraker, O. C. Incrg. Chem. 1969.8, 2680-2684. Reproduced with permission-]...

The Pb2 atoms have distorted icosahedral holmium coordination. These icosa-hedra show an orthorhombic body-centered packing. All three crystallographically independent holmium atoms are in the coordination sphere of the Pb2 atoms. 

The term rare earth elements is sometimes applied to the elements La-Lu plus yttrium. The convenience of including La, which, strictly speaking, is not a lanthanide, is obvious. The reason for including Y is that Y has radii (atomic, metallic, ionic) that fall close to those of erbium and holmium and all of its chemistry is in the trivalent state. Hence it resembles the later lanthanides very closely in its chemistry and occurs with them in Nature. 

Notice that Moseley had made a minor mistake in the atomic number determinations of both holmium and dysprosium. The atomic number of holmium is namely 67, and dysprosium has an atomic number of 66. It also appears that Moseley attached some credence to the investigation of Auer von Welsbach who had demonstrated the complexity of thulium in 1911 by splitting it into three components. Moseley had incorporated two of these components (Tml and Tmll) in his atomic number sequence. Moseley therefore ascribed Urbain s neo-ytterbium and lutetium too high an atomic number (in reality the atomic numbers of ytterbium and... 

Lanthanide elements (referred to as Ln) have atomic numbers that range from 57 to 71. They are lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). With the inclusion of scandium (Sc) and yttrium (Y), which are in the same subgroup, this total of 17 elements are referred to as the rare earth elements (RE). They are similar in some aspects but very different in many others. Based on the electronic configuration of the rare earth elements, in this chapter we will discuss the lanthanide contraction phenomenon and the consequential effects on the chemical and physical properties of these elements. The coordination chemistry of lanthanide complexes containing small inorganic ligands is also briefly introduced here [1-5]. 

V = 1.6874 (4) nm, and Z = 1. The compound is a square antiprism, consisting of the cen-trosymmetric dinuclear [H02(15)4(H2O)4(OH)2]4 cation, uncoordinated 15 molecules, and nitrate anions. The holmium atom is eight-coordinate with four nitrogens from the 15 ligands, two oxygens from H2O molecules, and two oxygens from hydroxo groups. 

Ho5(H20)i6(OH)2As6W64022o] is a linear cluster composed of six [B-a-AsW9033] fragments linked by a [Ho5Wio(H20)i6(OH)2022] belt. The five holmium atoms are eight-coordinated with a square-antiprism geometry [43]. 

Holmium occurs in Row 6 of the periodic table. The periodic table is a chart that shows how chemical elements are related to each other. Elements with atomic numbers 57 through 71 are known as the lanthanoids. The name comes from the first element in the series, lanthanum. The lanthanoids are also known as rare earth elements. Although lanthanoids are not especially rare, they were once very difficult to separate from each other. 

Only one naturally occurring isotope of holmium exists holmium-165. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element s name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope. 

Fifty radioactive isotopes of holmium are known also. A radioactive isotope is one that breaks apart and gives off some form of radiation. Radioactive isotopes are produced when very small particles are fired at atoms. These particles stick in the atoms and make them radioactive. None of the radioactive isotopes of holmium has any practical uses. 

Yttrium(III) lies on the same straight line if assigned an artificial atomic number of 67.5. i.e. between those of holmium and erbium. 

It is generally held that metal oxide perovskites with extrinsic oxygen vacancies react with atmospheric water. This entrains hydrogen into the lattice and leads to their significant proton conducting properties. The location of these hydrogen atoms was studied as a function of a series of dopants in a cerium based ceramic. The dopants were niobium, holmium... 

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