7440-07-5 Usage
History
Different sources of media describe the History of 7440-07-5 differently. You can refer to the following data:
1. Plutonium was discovered by Wahl, Seaborg, and Kennedy in 1941 at Berkeley, California when they separated and identified its isotope of mass 238 produced from bombarding uranium isotopes with neutrons in a cyclotron. In the same year the isotope Pu-239 was found to be fissionable. However, only microgram quantities of Pu-239 were generated by cyclotron bombardment. In 1943 Enrico Fermi and his group developed a process for successful generation of much larger quantities of plutonium for nuclear weapons. They achieved a self-sustaining nuclear chain reaction in a reactor using uranium and graphite. This work eventually led to the first successful testing of an atom bomb in the desert of New Mexico in July 1945.
2. The name of Pu derives from the planet Pluto, (the Roman god of the underworld). Pluto was selected because it is the next planet in the solar system beyond the planet Neptune and the element plutonium is the next element in the period table beyond neptunium. Plutonium was first synthesized in 1940 by American chemists Glenn T. Seaborg, Edwin M. McMillan, Joseph W. Kennedy and Arthur C. Wahl at Berkeley, California, in the nuclear reaction 238U(2H, 2n) 238Np → β ? → 238Pu. The longest half-life associated with this unstable element is 80 million year 244Pu.
Uses
Different sources of media describe the Uses of 7440-07-5 differently. You can refer to the following data:
1. Plutonium is the second transuranium element after neptunium. The element was named after the planet Pluto.
Plutonium is the most important transuranium element. Its two isotopes Pu-238 and Pu-239 have the widest applications among all plutonium isotopes. Plutonium-239 is the fuel for nuclear weapons. The detonation power of 1 kg of plutonium-239 is about 20,000 tons of chemical explosive. The critical mass for its fission is only a few pounds for a solid block depending on the shape of the mass and its proximity to neutron absorbing or reflecting substances. This critical mass is much lower for plutonium in aqueous solution. Also, it is used in nuclear power reactors to generate electricity. The energy output of 1 kg of plutonium is about 22 million kilowatt hours. Plutonium-238 has been used to generate power to run seismic and other lunar surface equipment. It also is used in radionuclide batteries for pacemakers and in various thermoelectric devices.
2. The principal plutonium isotopes, 239Pu and 240Pu, were
produced as ingredients for nuclear weapons. It is estimated
that the United States produced 400 kCi of plutonium for
nuclear weapons testing, and approximately 325 kCi was
dispersed globally into the environment from conducted
aboveground tests. Overall, an estimated 500 aboveground
nuclear tests were conducted between 1945 and 1963 by the
Soviet Union, Britain, France, and the United States. From these
tests, it is estimated 100 000 kCi of plutonium were dispersed
into the environment.Applications for 238Pu include using it as a heat source for
thermoelectric power devices. Radioisotope thermoelectric
generators (RTGs) have been used to provide a source of power
in remote locations, such as deep space probes. This plutonium
isotope generates a large amount of heat through its decay
process. The generated heat is converted into electric power via
a thermocouple in the RTG. Small-scale application of 238Pu is
also used to provide power to heart pacemakers. The concept behind the use of this material is a result of the half-life of the
isotope, since its half-life is extremely long, changing out the
power source is not necessary.
Reactions
Plutonium is a reactive metal forming mostly tri-, tetra-, and hexavalent compounds. The solutions of Pu3+ are blue. The trivalent Pu3+ is stable in solution in the absence of air. In the presence of air or oxygen, Pu3+ slowly oxidizes to Pu4+. In cold acid medium, permanganate ion oxidizes Pu3+ to Pu4+. In aqueous solutions Pu4+ salts impart pink or greenish color to the solutions. Tetravalent Pu4+ converts to hexavalent plutonium, Pu6+ by the action of strong oxidizing agents, such as dichromate, Cr2O7 2–, permanganate, MnO4 – or Ce4+ salts.
The metal ion in higher oxidation states can be reduced by most common reducing agents, such as, sulfur dioxide, carbon monoxide, ferrocyanide ion, hydrazine hydrochloride, and hydroxylamine hydrochloride to form Pu3+ (or Pu4+) ions in solution.
Plutonium combines with oxygen at high temperatures to form plutonium dioxide, PuO2 , and other oxides. The dioxide also is formed in the presence of water vapor. Ignition of the metal in air at 1,000°C yields PuO2. Plutonium reacts with hydrogen at high temperatures forming hydrides. With nitrogen, it forms nitrides, and with halogens, various plutonium halides form. Halide products also are obtained with halogen acids. Reactions with carbon monoxide yields plutonium carbides, while with carbon dioxide, the products are both carbides and oxides. Such reactions occur only at high temperatures.
Plutonium forms several complexes in oxidation states +3, +4, and +6.
Hazard
Plutonium is one of the most dangerous substances known. The metal and it’s salts are all highly toxic. Its ionizing radiation can cause cancer. The metal can incorporate with bone marrow forming insoluble plutonium (IV) phosphate. The metal only leaves the body very slowly. All operations must be carried out by remote control devices with proper shields. In production, processing, handling, and storage of large quantities of plutonium or its compounds one must bear in mind its critical mass, which can vary with the shape and the specific solid form or the quantities of plutonium contained in solutions.
Description
Plutonium was first isolated and produced in 1941 at the
University of California-Berkeley, by nuclear chemist Glenn T.
Seaborg and his colleagues, Joseph W. Kennedy, Edwin M.
McMillan, and Arthur C. Wahl. Minute amounts of plutonium
exist naturally, but large amounts are produced in nuclear
reactors when uranium absorbs an atomic particle such as a
neutron.
Natural occurrences of plutonium are very rare, but it can
occur in a reaction called spontaneous fission. This type of
reaction occurs when ores of uranium with a high localized
concentration decay in the right conditions and produce small
amounts of plutonium. Synthetic plutonium is produced in
a controlled nuclear reactor when uranium-238 absorbs
a neutron and becomes uranium-239, ultimately decaying to
plutonium-239. Plutonium has at least 15 different isotopes.
Different isotopes of uranium and different combinations of
neutron absorption and radioactive decay create the different
isotopes of plutonium. Plutonium was discovered during
wartime; therefore, the majority of plutonium production was
for nuclear weapons. Other plutonium applications range from
being energy sources on deep space probes to small amounts
providing power to heart pacemakers.
Chemical Properties
silvery white metal; highly reactive; αform: monoclinic, a=0.6183 nm, b=0.4822 nm, c=1.0963 nm; ionic radius of Pu++++ is 0.0887nm; stable form from room temp to 115°C; enthalpy of vaporization 333.5kJ/mol; enthalpy of fusion 2.82kJ/mol; discovered in 1940–1941; prepared in ton quantities in nuclear reactors; 238Pu produced in kg amounts from 237Np; important fuel for producing power for terrestrial and extraterrestrial applications [MER06] [KIR78] [CRC10]
Environmental Fate
Plutonium was dispersed in the environment by fallout from
aboveground weapons testing that occurred from the 1940s
through the 1960s. Approximately one-fifth of the plutonium
fallout from a nuclear weapons test remained on the test site.
The remaining plutonium fallout was released into the atmosphere,
absorbed to particulate matter, and transported back to
the surface by either dry or wet deposition. Additional releases
can be traced to accidental reactor effluent releases, improper
disposal of radioactive waste, and military accidents. Each
release directly introduced plutonium into the ecosystem,
where it has stayed.
Plutonium and its isotopes have relatively long half-lives.
The most common plutonium isotopes are 238Pu, 239Pu,
and 240Pu. The decay process for each of these varies, and all
are extremely long in duration. 238Pu (the principal isotope
for satellites) has a half-life of 87.7 years, 239Pu (a principal
isotope for nuclear weapons) has a half-life of 24 100 years,
and 240Pu has a half-life of 6560 years. Plutonium undergoes
a change in form through radioactive decay. As each of these
isotopes decay, they release energy and form a new product.
The energy being released is referred to as radiation. Plutonium
reactions in the environment are either oxidative or
reductive reactions. Plutonium can be found in five different
oxidations states: plutonium(III), plutonium(IV), plutonium(
V), plutonium(VI), and plutonium(VII).Most atmospheric and underwater nuclear weapons
testing were stopped by the Partial Test Ban Treaty of 1963.
The treaty did not cease the testing of nuclear weapons, it
only banned testing aboveground, and the testing continued
underground until the 1980s. Although the move to test
underground was to reduce the release of plutonium into
the environment, releases still occurred via test venting.
Plutonium can migrate vertically at various rates depending
on meteorological conditions, the form of plutonium as it
enters the environment, and human activity. However,
almost all plutonium introduced into the environment can
be found in the surface soil. Soil particles are the primary
mode of distribution. Plutonium compounds are ionic and
will not volatilize from the soil. Surface soils contaminated
with plutonium have been known to resuspend in the
atmosphere via fugitive dust emissions, causing it to be
rereleased into the environment. Parameters such as particle
size, presence of organic substances, and soil pH can
influence the distribution of the plutonium isotopes in
the soil and sediment. It has been documented in arctic
surface sediment studies that the partition coefficients (Kd) for 239，240Pu range from 8 × 10+4 to 1.5 × 10+5. Plutonium
fallout from the atmosphere can be deposited as insoluble
dioxide. This is an important factor since microorganisms
can change the oxidation state of plutonium, potentially
causing it to increase or decrease in solubility. But microorganism
changes occur only in a small fraction of the
plutonium released into the environment and this is based
on the released plutonium form. If the plutonium does
enter the soluble phase, it can become available for plant
uptake. Studies have shown that the plutonium(IV) oxidation
state is able to hydrolyze in the environment, and
plants can readily uptake the contaminant.Atmospheric plutonium fallout can reach surface water
and settle in the sediment under the water. The long halflives
of plutonium isotopes allow for contaminated sediment
to act as a repository, and eventually the contaminants
can resuspend in the water column, reintroducing them into
the environment. How plutonium in surface water acts is
dependent on the oxidation state of the released plutonium
and the nature of the suspended particulates in the environment.
It has been reported that plutonium in water with
suspended solids have Kd values ranging from 1 × 10+5 to
7 ×10+5. It was also reported that plutonium with colloidal
materials can be mobile in groundwater systems over long
distances. Plutonium(III) and plutonium(IV) are considered to
be reduced forms of plutonium, while plutonium(V) and
plutonium(VI) are oxidized forms. The primary oxidative state
of plutonium in the environment is plutonium(IV).
Toxicity evaluation
The toxicity of plutonium is based on the radiation emitted
during the exposure and radiological decay of the plutonium
isotope. Radiation emitted by plutonium can have many
different mechanistic impacts on cells, including ionization
and destruction of cell constituents that can result in a variety of
effects ranging from cell death with/without regeneration to
cells growing out of control if the DNA damage resulting is not
arrested by normal healthy body repair mechanisms. Additional
factors of toxicity include the radiosensitivity of the
tissue exposed and the retention time. Tissues that undergo
rapid cell regeneration are more sensitive than slower or nonregenerating
cells.
Check Digit Verification of cas no
The CAS Registry Mumber 7440-07-5 includes 7 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 4 digits, 7,4,4 and 0 respectively; the second part has 2 digits, 0 and 7 respectively.
Calculate Digit Verification of CAS Registry Number 7440-07:
(6*7)+(5*4)+(4*4)+(3*0)+(2*0)+(1*7)=85
85 % 10 = 5
So 7440-07-5 is a valid CAS Registry Number.
InChI:InChI=1/Pu
