Transuranium elements table

Fig. 4. Futuristic periodic table showing predicted locations of a large number of transuranium elements (atomic numbers in parentheses).

A further group of elements, the transuranium elements, has been synthesized by artificial nuclear reactions in the period from 1940 onwards their relation to the periodic table is discussed fully in Chapter 31 and need not be repeated here. Perhaps even more striking today are the predictions, as yet unverified, for the properties of the currently non-existent superheavy elements.Elements up to lawrencium (Z = 103) are actinides (5f) and the 6d transition series starts with element 104. So far only elements 104-112 have been synthesized, ) and, because there is as yet no agreement on trivial names for some of these elements (see pp. 1280-1), they are here referred to by their atomic numbers. A systematic naming scheme was approved by lUPAC in 1977 but is not widely used by researchers in the field. It involves the use of three-letter symbols derived directly from the atomic number by using the... 

Some of the reactions used to prepare transuranium elements are listed in Table 19.1. Neutron bombardment is effective for the lower members of the series (elements 93 through... 

The transuranium elements are the elements following uranium in the periodic table. The elements from rutherfordium (Rf, Z = 104) through meitnerium... 

The third principal component of environmental radioactivity is that due to the activities of humans, the anthropogenic radionuclides. This group of nuclides includes the previously discussed cases of 3H and 14C along with the fission products and the transuranium elements. The primary sources of these nuclides are nuclear weapons tests and nuclear power plant accidents. These events and the gross nuclide releases associated with them are shown in Table 3.1. Except for 14C and... 

In this chapter, we will discuss how to make these elements, their chemical properties, and their presence in the environment. The current list of transuranium elements is shown in Table 15.1 with a modem view of their place in the periodic table being shown in Figure 15.1. 

Figure 15.1 Modem periodic table showing the transuranium elements. (Figure also appears in color figure section.)...

The synthesis reactions used to discover the transuranium elements are given in Table 15.2. All these reactions are complete fusion reactions in which the reacting nuclei fuse, equilibrate, and deexcite in a manner independent of their mode of formation. Other production reactions involving a partial capture of the projectile nucleus are also possible. 

The chemical behavior of the transuranium elements is interesting because of its complexity and the insights offered into the chemistry of the lighter elements. The placing of these manmade elements into the periodic table (Fig. 15.1) represents one of the few significant alterations of the original periodic table of Mendelyeev. Since so little is known about the chemistry of the transactinide elements, one has the unique opportunity to test periodic table predictions of chemical behavior before the relevant experiments are done. 

Figure 15.1 Modern periodic table showing the transuranium elements.

The transuranium elements are the elements following uranium in the periodic table. The elements from rutherfordium (Rf, Z = 104) through meitnerium (Mt, Z = 109) were formally named in 1997. The transmeitnerium elements, the elements beyond meitnerium (including hypothetical nuclides that have not yet been made), are named systematically, at least until they have been identified and there is international agreement on a permanent name. The systematic nomenclature uses the terms in Table 17.2. For example, the element with Z = 111, one atom of which was first made in 1994, will be called unununium, Uuu, until it is finally named. 

The M(OR) derivatives are known now for almost all the elements of the Periodic Table (including the transuranium elements and Xenon). They are formal analogs of hydroxides but possess much higher thermal stability. Their properties are determined not only by the electronegativity of the metal atom but also by the nature of the radical — its ramification and the acidity of the corresponding alcohol, which provides their various properties. From this point of view they can be subdivided into the following groups of compounds ... 

Transuranium elements The elements following uranium (atomic number 92) in the periodic table. 

The actinides include another part of the periodic table called the transuranium elements, which begin with neptunium (atomic number 93) and end with roentgenium (atomic number 111) back up in Period 7. Neptunium and plutonium are the only... 

The lanthanide and actinide elements are located at the bottom of the periodic table in two rows separate from the rest of the elements. By atomic number, they should be located in Periods 6 and 7, but they have special properties that distinguish them from elements in those periods. Lanthanides are very similar to each other and have some industrial uses. Many of the actinides were discovered as part of the first atomic bomb experiments. They are highly radioactive and have few uses. The transuranium elements were mostly created in the laboratory and are very short-lived. 

The information presented in this chapter will be included in the material property database for f-elements and compounds (/-MPD) of the Institute of Transuranium Elements, which is accessible through internet.3 Complete thermodynamic tables can be retrieved at that site, which will be updated regularly with new information. 

In contrast, the chemists were left with little but fission debris - the earliest instance of radioactive fallout. The chemical data from the uranium investigation was essentially meaningless - the transuranium elements that had inspired such confidence turned out to be a messy cocktail of light elements from across the periodic table. [38] Moreover, chemists had not broken new ground with the fission discovery, since they were still saddled with the assumption that transuranium elements were transition elements. 

In the years since 1940 the elements with atomic numbers 93 through 112 and 114, 116, and 118, called the transuranium elements, have been synthesized. Many of these elements have very short half-lives, as shown in Table 21.4. As a result, only a few atoms of some of the transuranium elements have ever been formed. This, of course, makes the chemical characterization of these elements extremely difficult. 

Of special interest was the discovery of the transuranium elements, because this meant an extension of the Periodic Table of the elements. At present, 23 transuranium elements are known, beginning with elements 93 (Np = neptunium),... 

At one time it was considered exireniely unlikely that there would be any significant chemistry for elenients with atomic numbers greater than about lOO. The nuclear stability of the transuranium elenients decreases with atomic number, so that the half-lives for the heaviest elements (Table 14.5) become too short for fruitful chemical studies (i.e., n = seconds). However, advanced chemical techniques have helped... 

---