Isotopes artificially produced

All naturally occurring beryllium compounds are. made up of the Be isotope. Artificially produced isotopes occur during some nuclear reactor operations and include 6Be, 7 Be, sBe, and l0Be. 

Few of the naturally occurring elements have significant amounts of radioactive isotopes, but there are many artificially produced radioactive species. Mass spectrometry can measure both radioactive and nonradioactive isotope ratios, but there are health and safety issues for the radioactive ones. However, modem isotope instmments are becoming so sensitive that only very small amounts of sample are needed. Where radioactive isotopes are a serious issue, the radioactive hazards can be minimized by using special inlet systems and ion pumps in place of rotary pumps for maintaining a vacuum. For example, mass spectrometry is now used in the analysis of Pu/ Pu ratios. 

F is the remaining fraction of 38Ar at temperature t °C. t is derived from 37At outgassing data because this isotope is artificially produced by a nuclear reaction between fast neutrons and Ca. 

Sulfur-35 does not occur in nature it is an artificially produced isotope. 

Matsson and coworkers have measured the carbon-1 l/carbon-14 kinetic isotope effects for several Menshutkin reactions (equation 35) in an attempt to model the S/v2 transition state for this important class of organic reaction. These isotope effects are unusual because they are based on the artificially-made radioactive carbon-11 isotope. The radioactive carbon-11 isotope is produced in a cyclotron or linear accelerator by bombarding nitrogen-14 atoms with between 18- and 30-MeV protons (equation 36). 

Isotrope, Having the same atomic number (and position in the Periodic Table of Elements) but different masses. The difference is due to extra neutrons in the nucleus. For example hydrogen, one of three isotopes, has an atomic number of 1 and a mass of 1 the naturally occurring deuterium has a mass of 2 because it has an extra neutron in its nucleus the artificially produced tritium has another neutron for a mass of three. All three have one proton and electron and, hence, an atomic number of 1. 

Only about one ounce of natural francium exists in the Earths crust. All the other isotopes of francium are artificially produced in very small amounts (just a few atoms at a time) that exist for a few seconds to minutes. 

All the other eight Isotopes are radioactive and artificially produced with half-lives ranging from Be-8 = 0.067 seconds to Be-14 = 1.6x 10 years. 

ISOTOPES There are 26 isotopes of the element chromium four are stable and found in nature, and the rest are artificially produced with half-lives from a few microseconds to a few days. The four stable isotopes and their percentage of contribution to the total amount of chromium on Earth are as follows °Cr = 4.345%, Cr = 83.789%,... 

ISOTOPES There are 32 known isotopes of copper, ranging from Cu-52 to Cu-80. Only two of these 32 isotopes of copper are stable, and together they make up the amount of natural copper found In the Earth s crust In the following proportions Cu-63 = 69.17% and Cu-65 = 30.83%. All the other Isotopes of copper are radioactive and are artificially produced with half-lives ranging from a few nanoseconds to about 61 hours. 

ISOTOPES There are 38 isotopes of zinc, ranging in atomic weights from Zn-54 to Zn-83. Just four of these are stable, and those four, plus one naturally radioactive isotope (Zn-70) that has a very long half-life (5x10+ years), make up the element s existence on Earth. Their proportional contributions to the natural existence of zinc on Earth are as such Zn-64 = 48.63%, Zn-66 = 27.90%, Zn-67 = 4.10%, Zn- 68 = 18.75%, and Zn-70 = 0.62%. All the other isotopes are radioactive and artificially produced. 

The major characteristic of technetium is that it is the only element within the 29 transition metal-to-nonmetal elements that is artificially produced as a uranium-fission product in nuclear power plants. It is also the tightest (in atomic weight) of all elements with no stable isotopes. Since all of technetiums isotopes emit harmful radiation, they are stored for some time before being processed by solvent extraction and ion-exchange techniques. The two long-lived radioactive isotopes, Tc-98 and Tc-99, are relatively safe to handle in a well-equipped laboratory. 

Since all of technetium s isotopes are produced artificially, the element s atomic weight (atomic mass units) is determined by which isotopes are selected for the calculation. 

ISOTOPES There are 42 isotopes of palladium, ranging from Pd-91 to Pd-124. All but six are radioactive and artificially produced in nuclear reactors with half-lives ranging from 159 nanoseconds to 6.5x10+ years. The six stable isotopes of palladium and their proportional contribution to their existence in the Earth s crust are as follows Pd-102 = 1.02%, Pd-104 = 11.14%, Pd-105 = 22.23%, Pd-106 = 27.33%, Pd-108 = 26.46%, and Pd-110= 11.72%. 

ISOTOPES There are 52 isotopes of cadmium. Forty-four are radioactive and artificially produced, ranging from Cd-96 to Cd-131. Of these 52 isotopes, there are five stable isotopes plus three naturally occurring radioactive isotopes with extremely long half-lives that are considered as contributing to the element s natural occurrence in the Earth s crust. The three naturally radioactive isotopes (Cd-106, Cd-113, and Cd-116) are the longest known beta emitters. They are two million years older than when the solar system was formed about 4.5 billion years ago. The five stable isotopes and their proportional contributions to the elemenfs existence on Earth are as follows Cd-108 = 0.89%, Cd-110 = 12.49%, Cd-111= 12.80%, Cd-112 = 24.13%, and Cd-114 = 28.73%. 

ISOTOPES There are 55 Isotopes of Iridium, two of which are stable and account for the element s total existence on Earth. Those two are lr-191, which makes up 37.3% of the amount In the Earth s crust, and lr-193, which constitutes 62.7% of Iridium s existence on Earth. All the other 53 Isotopes of Iridium are radioactive with half-lives ranging from a few microseconds to a few hours or days and up to a few hundred years. These unstable Isotopes are all artificially produced. 

ISOTOPES There are a total of 54 isotopes of gold, only one of which is stable Au-197, which accounts for the element s total natural existence on Earth. The remaining 53 isotopes are radioactive, are artificially produced in nuclear reactors or particle accelerators, and have half-lives ranging from a few microseconds to a few seconds to a few hours to a few days. 

ISOTOPES There are a total of 25 isotopes of chlorine. Of these, only two are stable and contribute to the natural abundance on Earth as follows Cl-35 = 75.77% and Cl-37 = 24.23%. All the other 23 isotopes are produced artificially, are radioactive, and have half-lives ranging from 20 nanoseconds to 3.01 x 10+ years. 

ISOTOPES There are 45 isotopes of praseodymium. All are artificially produced and radioactive with half-lives ranging from several hundred nanoseconds to 23.6 days. Only one is stable (Pa-141), and it makes up 100% of the praseodymium found in the Earth s crust. 

ISOTOPES There are a total of 45 Isotopes of europium. Two are considered stable and account for 100% of the europium found on Earth Eu-151 (47.81%) and Eu-153 (52.19%). All the other 53 Isotopes are radioactive and artificially produced, primarily through electron capture. 

ISOTOPES There are a total of 46 isotopes of thulium. One of these, Tm-169 is the only stable isotope of thulium and accounts for the total atomic mass of the element. All the other isotopes are artificially produced and radioactive and have half-lives ranging from a few microseconds to two years. 

At one time, neptunium s entire existence was synthesized by man. Sometime later, in the mid-twentieth century, it was discovered that a very small amount is naturally produced in uranium ore through the actions of neutrons produced by the decay of uranium in the ore pitchblende. Even so, a great deal more neptunium is artificially produced every year than ever did or does exist in nature. Neptunium is recovered as a by-product of the commercial production of plutonium in nuclear reactors. It can also be synthesized by bombarding uranium-238 with neutrons, resulting in the production of neptunium-239, an isotope of neptunium with a half-life of 2.3565 days. 

AH the isotopes of americium belonging to the transuranic subseries of the actinide series are radioactive and are artificially produced. Americium has similar chemical and physical characteristics and is hofflologous to europium, located just above it in the rare-earth (lanthanide) series on the periodic table. It is a bright-white malleable heavy metal that is somewhat similar to lead. Americiums melting point is 1,176°C, its boiling point is 2,607°C, and its density is 13.68g/cm. ... 

There is no natural curium on Earth. All of its isotopes are man-made and artificially produced through nuclear reactions with other elements. The curium isotope Cm-242 was first produced by bombarding plutonium-239 with helium nuclei (alpha particles), which contributed neutrons that changed Pu to g Cm. 

Berkelium is a metallic element located in group 11 (IB) of the transuranic subseries of the actinide series. Berkelium is located just below the rare-earth metal terbium in the lanthanide series of the periodic table. Therefore, it has many chemical and physical properties similar to terbium ( Tb). Its isotopes are very reactive and are not found in nature. Only small amounts have been artificially produced in particle accelerators and by alpha and beta decay. 

The pure metal of berkelium does not exist in nature and has never been directly artificially produced, although the first isotope of berkelium produced was berkelium-243. It was artificially formed by bombarding americium-241 with the nuclei of helium (alpha particles), as follows " Am+lalpha particle = 2 protons + 2 neutron)—> Bk. (Note Two protons as well as two neutrons are found in the nucleus of helium, and thus the two protons changed the atomic number of americium [ jAm] to berkelium [j Bk].) Today a different process is used to produce berkelium in small amounts, as follows Cm+(5n = neutrons X = gamma rays) —> (becomes) —> Bk + P- = (beta-minus decay). 

ISOTOPES There are a total of 21 isotopes of californium. None are found in nature and all are artificially produced and radioactive. Their half-lives range from 45 nanoseconds for californium-246 to 898 years for californium-251, which is its most stable isotope and which decays into curium-247 either though spontaneous fission or by alpha decay. 

Californium is a synthetic radioactive transuranic element of the actinide series. The pure metal form is not found in nature and has not been artificially produced in particle accelerators. However, a few compounds consisting of cahfornium and nonmetals have been formed by nuclear reactions. The most important isotope of cahfornium is Cf-252, which fissions spontaneously while emitting free neutrons. This makes it of some use as a portable neutron source since there are few elements that produce neutrons all by themselves. Most transuranic elements must be placed in a nuclear reactor, must go through a series of decay processes, or must be mixed with other elements in order to give off neutrons. Cf-252 has a half-life of 2.65 years, and just one microgram (0.000001 grams) of the element produces over 170 mhhon neutrons per minute. 

Californium is a transuranic element of the actinide series that is homologous with dysprosium (gjDy), just above it in the rare-earth lanthanide series. Cf-245 was the first isotope of californium that was artificially produced. It has a half-life of just 44 minutes. Isotopes of californium are made by subjecting berkelium to high-energy neutrons within nuclear reactors, as follows + (neutrons and A, gamma rays) — °Bk — °Cf + (3- (beta particle... 

Neither californium nor its compounds are found in nature. All of its isotopes are produced artificially in extremely small amounts, and all of them are extremely radioactive. All of its isotopes are produced by the transmutation from other elements such as berkelium and americium. Following is the nuclear reaction that transmutates californium-250 into cahfornium-252 Cf + (neutron and A, gamma rays) — Cf + (neutron and A, gamma rays) —> Cf. 

ISOTOPES There are a total of 21 isotopes of fermium. Their half-lives range from fer-mium-258 s 370 microseconds to fermium-257 s 100.5 days, which is the longest of all its isotopes. None of fermium s isotopes exist in nature. All are artificially produced and are radioactive. 

Fermium does not exist in nature. All of it is artificially produced in cyclotrons, isotope particle accelerators, or nuclear reactors by a very complicated decay process involving six steps of nuclear bombardment followed by the decay of beta particles, as follows ... 

ISOTOPES There a total of 15 isotopes of nobelium, ranging from 0,25 milliseconds (No-250) to 58 minutes (No-59). None are found in nature all are unstable and are artificially produced In cyclotrons. 

ORIGIN OF NAME Named after and in honor of the nuclear chemist Glenn T. Seaborg. ISOTOPES There a total of 16 Isotopes of unnilhexium (seaborgium) with half-lives ranging from 2.9 milliseconds to 22 seconds. All are artificially produced and radioactive, and they decay by spontaneous fission (SF) or alpha decay. 

Not many chemical and physical properties of Une (or Mt) are known, but it is artificially produced by the basic process of combining the isotopes of two elements to produce a few atoms of a heavier isotope in linear accelerators. In this case, the creation of a few atoms of element 109 involves a similar nuclear process of fusion as was used for element 108. The reaction follows ... 

ISOTOPES There are four isotopes of ununbium ranging from Uub-277 to Uub-285. They have half-lives ranging from 0.24 milliseconds to 10 minutes for Uub-285. All are artificially produced, are radioactive, and are unstable. 

More than 99% of natural thorium exists in the form (isotope) thorium-232. Besides this natural thorium isotope, there are more than 10 other different isotopes that can be artificially produced. In the environment, thorium-232 exists in various combinations with other minerals, such as silica. Most thorium compounds commonly found in the environment do not dissolve easily in water and do not evaporate from soil or water into the air. 

This work was carried on by B. B. Cunningham and L. B. Werner. On August 18, 1942, they isolated about one microgram of a pure compound. This was the first sight of a synthetic element and the first case of the isolation of a weighable amount of an artificially produced isotope (71, 59, 69). In September, 30 micrograms of the element were obtained and the iodate, hydroxide, peroxide, and ammonium plutonium fluoride were prepared in a pure state. 

The use of isotopes in mechanistic and analytical chemistry has been known since about 1913 but it was the advent of artificially produced isotopes in the period from 1945 onwards that really marked the beginning of a wide range of isotopic tracer techniques. There is now an extensive literature on tracer techniques and a few of the more useful references are included at the end (7—5). 

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