What type of decay does thorium undergo

The nuclear disintegration process that emits alpha particles is called alpha decay. An example of a nucleus that undergoes alpha decay is uranium Where does an alpha particle get this symbol? The bottom number in a nuclear symbol is the number of protons. That means that the alpha particle has two protons in it which were lost by the uranium atom.

The top number, 4, is the mass number or the total of the protons and neutrons in the particle. Because it has 2 protons, and a total of 4 protons and neutrons, alpha particles must also have two neutrons. Alpha particles always have this same composition: two protons and two neutrons. Alpha decays occur with radioactive isotopes of radium, radon, uranium, and thorium.

Another common decay process is beta particle emission, or beta decay. A beta particle is simply a high energy electron that is emitted from the nucleus. It may occur to you that we have a logically difficult situation here. Nuclei do not contain electrons and yet during beta decay, an electron is emitted from a nucleus. At the same time that the electron is being ejected from the nucleus, a neutron is becoming a proton.

It is tempting to picture this as a neutron breaking into two pieces with the pieces being a proton and an electron. That would be convenient for simplicity, but unfortunately that is not what happens; more about this at the end of this section.

For convenience sake, though, we will treat beta decay as a neutron splitting into a proton and an electron. The proton stays in the nucleus, increasing the atomic number of the atom by one. The electron is ejected from the nucleus and is the particle of radiation called beta.

To insert an electron into a nuclear equation and have the numbers add up properly, an atomic number and a mass number had to be assigned to an electron. The mass number assigned to an electron is zero 0 which is reasonable since the mass number is the number of protons plus neutrons and an electron contains no protons and no neutrons. The atomic number assigned to an electron is negative one -1 , because that allows a nuclear equation containing an electron to balance atomic numbers.

Therefore, the nuclear symbol representing an electron beta particle is. Thorium is a nucleus that undergoes beta decay. Here is the nuclear equation for this beta decay.

Frequently, gamma ray production accompanies nuclear reactions of all types. Uranium entering the body becomes concentrated in the bones because uranium forms complexes with phosphate ions. Neptunium is a silver, radioactive, artificially produced element. It is named for the planet Neptune, since Neptune follows Uranus in the solar system. It is found in uranium ores at very low concentrations, but the commercial source for neptunium is from spent uranium fuel rods from nuclear reactors.

The two longest-lived isotopes of neptunium are neptunium, which has a half-life of 2,, years, and neptunium, with a half-life of , years. All of the other isotopes have half-lives that range from a few minutes to a little over a year. Neptunium is the first of the transuranium elements , which have higher atomic numbers than uranium. With very few exceptions, the transuranium elements are too rare, and too dangerous, to find much commercial use.

Neptunium was first prepared in by Edwin M. McMillan and Philip H. Abelson at the University of California in Berkeley, California by bombarding uranium with neutrons, producing uranium, which underwent beta decay to produce neptunium Uranium can also be converted to neptunium by neutron bombardment, absorbing two neutrons to produce uranium, which then undergoes beta decay to produce neptunium Uranium can also absorb one neutron, emit two more neutrons and become uranium, which then undergoes beta decay to produce neptunium Plutonium is a silver, radioactive, artificially produced element.

It is named for the planet well, ex-planet of Pluto, since Pluto follows Neptune usually in the solar system. Its discoverer, Glenn T. Seaborg chose the symbol "Pu" for the element, rather than "Pl" "partly to avoid confusion with platinum, Pt, but also 'facetiously,' he says, 'to create attention' — P. Plutonium was first synthesized by Glenn T. Seaborg, Arthur C. Wahl, and Joseph W. Kennedy at the University of California in Berkeley, California in , although its existence was not reported publicly until because of the security restrictions surrounding nuclear research and the Manhattan Project to build the first atomic bombs.

Uranium was bombarded with neutrons to produce uranium, which then underwent beta decay to produce neptunium, which also underwent beta decay to produce plutonium The longest-lived isotope of plutonium is plutonium, which has a half-life of 82,, years; plutonium and also have fairly long half-lives, of , years and 24, years. The most commonly used isotopes are plutonium half-life of Plutonium is not fissionable, and emits alpha particles without also emitting gamma rays, making it a great deal safer to handle.

It is used primarily as a long-lived power source in pacemakers, spacecraft and satellites, and deep-sea diving suits. Plutonium is fissionable, and is used in atomic weapons. The critical mass for plutonium is about 16 kg, but this can be reduced by surrounding the plutonium with a shell of beryllium, which reflects neutrons back towards the plutonium, accelerating the fusion process. One kilogram of plutonium has the explosive equivalent of 20, tons of TNT.

Plutonium half-life of 6, years is a contaminant in weapons-grade plutonium; since this isotope emits neutrons when it undergoes spontaneous fission, plutonium cannot be used in a gun-type device as uranium can see entry for uranium , because the device would be blown apart before a critical mass of plutonium can undergo much fission.

This requires plutonium-based weapons to use a more complicated implosion design. Plutonium was a component of the first atomic bomb to be detonated, at the Trinity test site near Alamagordo, New Mexico on July 16, In this device, a shell of plutonium was imploded by conventional explosives, which compressed the plutonium together to form a critical mass; the explosion was initiated by a shower of neutrons emitted by a polonium source. The first atomic bomb used in warfare was dropped on Hiroshima, Japan, on August 6, , but this one used uranium only.

The "Fat Man" atomic bomb that was exploded in Nagasaki, Japan on August 9, was also a plutonium bomb which had the destructive potential of approximately 21, tons of TNT, and killed over 70, people.

Plutonium bombs are also used to initiate the explosion of hydrogen bombs, which are powered by nuclear fusion instead of fission see entry for Hydrogen on the Group 1A page. Americium is a silvery, synthetic, radioactive metal, produced by the neutron bombardment of plutonium.

It was first made by Glenn T. Seaborg, Ralph A. James, Leon O. Morgan, and Albert Ghiorso at the University of Chicago in It was named for the American continent because of its chemical similarities to europium the element immediately above it in the lanthanide series , which named for Europe. The longest-lived isotope, americium, has a half-life of years; americium has a half-life of years.

Americium is used in gas and smoke detectors, in the form microgram quantities of americium oxide, AmO 2. The alpha particles that the isotope emits ionizes the air in the space between the electrodes in the detector, causing an electrical current to flow between the electrodes. When smoke enters the detector, the current flow is interrupted or reduced because the ions are absorbed by the smoke particles, triggering the alarm to sound.

The alpha particles emitted by the americium do not pose any health hazard, because they are easily blocked by the metal and plastic in the detector housing, and pick up electrons to become harmless helium atoms.

Curium is a silvery, synthetic, radioactive metal, produced by bombarding plutonium with alpha particles. It was named in honor of Marie and Pierre Curie, the co-discovers of radioactivity. The longest-lived isotope, curium, has a half-life of 16,, years. Berkelium is a silvery, synthetic, radioactive metal, produced by bombarding americium with alpha particles. It was first made by Stanley G.

Thompson, Albert Ghiorso, and Glenn T. Seaborg at the University of California, Berkeley, in It was named in honor of Berkeley, California, where it was first produced. An accelerator driven system by definition is a subcritical nuclear reactor and will remain operational as long as the neutrons from an external source are injected into the reactor.

Such a reactor cannot melt down ; a meltdown is a situation where the heat of a nuclear reaction cannot be contained and the reactor core melts. In addition, the thorium used in nuclear reactors is used as the chemical thorium dioxide which at degrees Celsius has the highest melting point of any oxide. This provides far better thermal and physical properties than the uranium oxide used in conventional reactors. Depending on the fuel cycle used, the energy content of thorium can be used almost in its entirety.

Virtually all natural thorium is thorium and is potentially useable in a reactor compared to 0. The ores of thorium are in abundance in Australia although they are geographically dispersed. With little change to current sand mining practices, monazite can be readily extracted for its thorium and rare earth mineral content, rather than being discarded. Not all technical problems have yet been solved in the development of fuel cycles based on thorium.

Firstly, it is difficult and expensive to fabricate fuel for closed cycle thorium reactors. Uranium, chemically separated from irradiated thorium, is highly radioactive and hence hard to handle for fuel assembly fabrication.

In addition, separated uranium is always contaminated with uranium Uranium is radioactive, has a half life of Secondly, there are technical difficulties in recycling thorium due to the high radioactivity of thorium which is a decay product of the contaminant uranium Thirdly, there is some nuclear proliferation risk with uranium if it can be separated. And fourthly, there are technical problems in reprocessing spent fuel from these reactors.

Were the technical difficulties to be resolved, it is by no means clear that Australia s environmental movement would accept a thorium-based nuclear future for Australia. Two states New South Wales and Western Australia have current bans on the mining of thorium and influential organisations such as the Australian Conservation Foundation ACF are opposed to any nuclear industry in Australia. There are several advantages for Australia in pursuing a thorium-based nuclear future in preference to the conventional uranium-based reactors that are now central to the nuclear and climate change debate.

However, with technical problems yet to be resolved, the current relative abundance of uranium, and an environmental movement opposed to any nuclear activities in Australia, a thorium-based nuclear future does not appear likely in the short to medium term. ADS An accelerator driven subcritical system. This is a subcritical reactor. In simple terms an atom comprises a nucleus and a number of electrons.

It contains protons and neutrons. There are many different sorts of sub-atomic particle including the electron, the proton and the neutron. In simple terms, an element is a substance which cannot be changed into another substance by ordinary chemical processes.

Iron and lead, for example, are elements. A naturally-occurring element is found in nature and has not been manufactured using nuclear processes. A radioactive element is an element that has an unstable atomic nucleus this sort of element spontaneously and randomly alters the state of its atomic nucleus, emitting sub-atomic particles in the process.

Sub-atomic particles are the building blocks of atoms. There are many different sub-atomic particles; those mentioned here are the electron , and the proton and the neutron which in combination make up an atomic nucleus. The number that is part of the isotope name here is the isotope s atomic mass number. This mass number is the sum of the number of protons in the nucleus here 90 and the number of neutrons in the nucleus here The isotope thorium also occurs in the decay series of thorium, i.

Most of these are short-lived isotopes and hence more radioactive than thorium; they are negligible in mass. A diagram of the decay series follows in the next footnote. Thorium with an atomic mass number of eventually decays to lead with an atomic mass number of A mineral is a naturally-occurring homogeneous solid that has a definite chemical composition and a highly ordered atomic structure.

Rare-earth minerals are a group of elements once thought rare; the term is probably now a misnomer. Interestingly, monazite contains significant amount of helium caused by the alpha decay of thorium and uranium; the helium can be extracted by heating. In alpha decay the nucleus of an atom emits two protons and two neutrons this is identical to emitting a helium nucleus. Geoscience Australia, Australia s identified mineral resources , Geoscience Australia, Canberra, These mineral sands are often found in placer deposits which are accumulations of dense materials trapped by the flow of water.

Placer materials are dense materials that because of their density fail to be carried along by water flow and are left behind and concentrated in hollows and bends. The minerals in mineral sands are extracted for their titanium and zirconium content. Geoscience Australia, loc. Radiation is an occupational health issue in the mineral sands industry and heavy mineral sands production is managed under the Code of Practice for Mining and Milling of Radioactive Ores.

Current performance data indicate that current radiation levels are well below the recently set Commonwealth Radiation Protection Code limit for occupational exposure. Geoscience Australia, op. It does not imply that extraction is economic at that level because extraction is only economic if the market price exceeds the extraction cost. In the case of thorium there is no market price.

Other figures for thorium resources are at U. Note that estimates from different sources vary because of different assumptions underlying their compilation and different interpretations of the term reserves. Price and J. Blaise, Nuclear fuel resources: enough to last? Neutrons are sub-atomic particles typically found within the nucleus of atoms.