Living elements

Strongly radioactive, short-lived element that can be found in tiny amounts in uranium ores. It arises fleetingly from 235U in its decay chain through actinium (227Ac). Is only of scientific value as it has a maximum half-life of about 22 minutes. Nevertheless, in its short existence it is the atom with the largest diameter (0.270 nm cesium 0.265 nm). 

Radioactive, short-lived element. The longest-lived isotope (256Md) has a half-life of 55 days. To date, only a few atoms have been prepared by a nuclear reaction between einsteinium and helium nuclei in a particle accelerator. 

A study of life and how it develops from the non-living elements.) wholrabe, Raymond, Crystals, J. B. Lippincott Co., Philadelphia and New York, 1962... 

For the abundance in the ISM of a stable or very long-lived element at the time of Solar-System formation, we can take... 

The semiobjective method incorporates living elements in its sensors but joins these to instruments for value assignment. 

The use of aluminum rabbits meant that data on the short-lived elements obtained from the 5-min decay count would be lost. Significant personnel radiation exposures were obtained from handling the aluminum rabbit (.—50 g) directly from the reactor core because of the 1780 keV gamma of 2.2-min 28A1 and a remote method used to open the rabbit took too much time (in excess of 20 min). 

Website for the heavy-ion research facility in Darmstadt, Germany, where many of the heaviest but shortest-lived elements are being created... 

A variety of irradiation, decay, and counting schemes can be employed by NAA in order to enhance the sensitivities of different subsets of elements. For example, short irradiation times followed short decay times are used to measure the short-lived elements, and long irradiation times followed by long decay times are used to measure the long-lived elements. For obsidian, the short-lived... 

Heavy metals. The most common heavy-metal pollutants are arsenic, cadmium, chromium, copper, nickel, lead, and mercury. Some metals, such as manganese, iron, copper, and zinc, are essential micronutrients. Each type of heavy metal in its own way affects water ecosystem biochemistry and can accumulate in bottom deposits and in the biomass of living elements. 

Hypereutrophic water. Heavily polluted and highly productive water close to the state of wetland water. Many living elements of the ecosystem are at the point of extinction. The rate of CH4 emission reaches 10 mmol m 2 da 1 46 mmol m 2 da 1. 

The energy source for the entire system is solar radiation EA(t,p, X,z), the intensity of which depends on time t, latitude p, longitude A, and depth z. The equation that describes the biomass dynamics of living elements is... 

Let us now look at several results of this investigation. In the nuclear war scenario, for example, the SSMAE shows that Arctic environmental stability would be disturbed 3 months after the impact. From other scenarios, it follows that variations in the velocity of vertical advection from 0.004cm/s to 0.05 cm/s does not affect the Arctic environmental state. An error of 32% in ice area estimate leads to a variation in simulation results of 36%. When this error is more than 32%, simulation results become less stable and can vary by several times. The problem exists of finding the proper criterion to estimate SSMAE sensitivity to variations in model parameters. As Krapivin (1996) showed, a survivability function J(t) reflecting the dynamics of the total biomass of living elements would enable this sensitivity to be estimated. In this instance... 

A large variety of tools, from manual separation procedures to very sophisticated, automated computer-controlled apparatuses have been developed and are now at hand to study the chemical properties of these short-lived elements one-atom-at-a-time in the liquid phase and in the gas phase. It is demonstrated in Chapter 4 how this can be achieved, what kinds of set-ups are presently available and what the prospects are for future developments to further expand our knowledge. 

Seven of the twelve elements detected here Na, Al, Cl, K, Mn, Zn, and Br were also detected by Given et al. (1) in the polythene insulation of XlfE cable which failed in service. The other five were not detected, possibly because their neutron activation method for short-lived elements was not as sensitive as our method b. They also detected eleven other elements, probably because their material contained higher impurity concentrations, and they found that Na and Cl had migrated to regions containing water trees. 

Selective Cs and Sr precipitation methods are useful in trying to separate these long-lived elements from the rest of the fission products, in order to permit more rapid disposal of the short-lived residue. 

We have shown here how the chemical properties of the very heavy elements can be studied both experimentally and theoretically, each complementing the other and leading to an understanding of the chemistry of the very exotic short-lived elements. The... 

All elements beyond bismuth (Z=83) are radioactive, and none beyond uranium (Z= 92) occur naturally on Earth. With increasing numbers of protons heavier elements have progressively less stable nuclei with shorter half-lives. Elements with Zup to 110 have been made artificially but the half-lives beyond Lr (Z=103) are too short for chemical investigations to be feasible. Two lighter elements, technetium (Tc, Z=43) and promethium (Pm, Z=61), also have no stable isotopes. 

There are 280 naturally occurring nuclides that make up the 83 stable and long-lived elements. These are all the elements up to Bi with Z = 83, except for unstable Tc (Z = 43) and Pm (Z = 61) that only have short-lived isotopes, but the long-lived Th and U bring the total back to 83. Here long-lived or short-lived is with respect to the half-life of an isotope against radioactive decay and the age of the solar system. Long-lived means then an element is still present in measurable quantities since the solar system formed 4.6 Gyr ago, and radioactive isotopes with half-lives above 0.6 Gyr usually qualify... 

By 1996, elements up to 112 had all been created, many with extremely short half-lives. Element 112, for example, has a half-life of 240 microseconds. 

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