Holmium isotope

The first isotope of this element having mass number 253 and half-life 20 days was detected in 1952 in the Pacific in debris from the first thermonuclear explosion. The isotope was an alpha emitter of 6.6 MeV energy, chemically analogous to the rare earth element holmium. Isotope 246, having a half-life 7.3 minutes, was synthesized in the Lawrence Berkeley Laboratory cyclotron in 1954. The element was named Einsteinium in honor of Albert Einstein. Only microgram amounts have been synthesized. The element has high specific alpha activities. It may be used as a tracer in chemical studies. Commercial applications are few. 

Tin hold the record with 10 stable isotopes. There are 19 so-called "pure elements" of which there is only one isotope. These anisotopic elements are beryllium, fluorine, sodium, aluminum, phosphorus, scandium, manganese, cobalt, arsenic, yttrium, niobium, rhodium, iodine, cesium, praseodymium, terbium, holmium, thulium, gold, and bismuth. 

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. 

ISOTOPES There are a total of 57 isotopes of holmium. Only one of these, Ho-165, is stable, and it is the only isotope found in the Earth s crust. All the other 56 isotopes have half-lives of a few milliseconds to 1.20x10+ years, the half-life of Ho-166. 

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. 

HoLmium, Ho at, wt 164,9304 at. no. 67 valence 3. A rare earth metal or the yttrium group. One naturally occurring isotope 165Ho artificial radioactive isotopes ... 

Naturally occurring holmium has one stable isotope Ho with an atomic mass of... 

C b.p. 2695°C. It occurs in apatite, xenotime, and some other rare-earth minerals. There is one natural isotope, holmium-165 eighteen artificial isotopes have been produced. There are no uses for the element, which was discovered by Per Qeve (1840-1905) and J. L. Soret in 1879. 

Because copper has only two stable isotopes, only one tracer isotope is available, which limits the choice of techniques for metabolic studies substantially. In most human studies, Cu has been used to determine apparent absorption, as the difference between the amount of isotope ingested and the amount recovered in feces. To check for completeness of fecal collection, holmium has been suggested and successfully used as a non-absorbable, quantitative elemental marker in copper absorption studies [259]. Studies comparing copper absorption of foods intrinsically or extrinsicaUy labeled with Cu are limited. Johnson and co-workers [260, 261] found no statistically significant difference in copper absorption from intrinsically and extrinsicaUy labeled goose fiver, goose breast, peanut butter, and wheat. Harvey et al. [262] observed significant differences in copper absorption between intrinsically and extrinsicaUy labeled sunflower seeds and soy beans. 

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