7440-51-9 Usage
Uses
1. Used in Space and Medical Applications:
Curium is used as a power source in radionuclide batteries for space and medical applications, specifically with isotopes 242Cm and 244Cm.
2. Used as a Radioactive Heat Source:
Curium-242 is used as a radioactive heat source, providing heat through the nuclear decay of the radioisotope.
3. Used in Accelerator Studies:
Curium-248 is used in accelerator studies to form superheavy elements.
4. Used for Thermoelectric Power Generation:
In the future, curium may be used to provide power for small, compact thermoelectric sources of electricity by generating heat through the nuclear decay of radioisotope curium-241. These small, efficient power sources can be used in individual homes or remote regions to provide electricity to areas that cannot secure it from other sources. It could also be used as a source of electricity in spacecraft.
5. Used in Basic Scientific Laboratory Research:
Currently, curium's main use is for basic scientific laboratory research.
Note: There are no major commercial uses for curium due to the extremely small amount produced.
Production
Curium can be synthesized in a nuclear reactor by several methods. The first synthesis involved alpha particle bombardment of plutonium-239:
It may be synthesized by several other methods. Curium isotopes of lower mass numbers may be obtained by charged particle bombardments of plutonium239:
Curium-244 isotope may be obtained by irradiation of plutonium-239 by thermal neutrons:
Curium-242 isotope may be obtained in the same way from plutonium-239 by successive neutron capture and βˉ decay:
Also, higher isotopes of curium may be produced from curium-242 by neutron capture reactions.
The heavier isotopes of the element may result from rapid neutron capture process caused by intense neutron fluxes from thermonuclear explosions, followed by a series of β–decay
Isotopes
There are 23 isotopes of curium. All of them are man-made and radioactive.The most stable is curium-247, with a half-life of 1.56×10+7years (156,600,000 years),which through alpha decay transmutates into plutonium-243.
Origin of Name
Named after Pierre and Marie Curie.
Characteristics
Curium is a synthetic (not natural) transuranic element of the actinide series. It was determinedthat curium’s major valence and oxidation state was +3, similar to other elements of thisseries. The most stable isotope of curium is curium-247, with a half-life of 1.56×10+7years.
History
Although
curium follows americium in the periodic system, it was actually
known before americium and was the third transuranium
element to be discovered. Curium was identified by Seaborg, James,
4-10 The Elements
and Ghiorso in 1944 at the wartime Metallurgical Laboratory
in Chicago as a result of helium-ion bombardment of 239Pu in
the Berkeley, California, 60-inch cyclotron. Visible amounts
(30 μg) of 242Cm, in the form of the hydroxide, were first isolated
by Werner and Perlman of the University of California in
1947. In 1950, Crane, Wallmann, and Cunningham found that
the magnetic susceptibility of microgram samples of CmF3 was
of the same magnitude as that of GdF3. This provided direct
experimental evidence for assigning an electronic configuration
to Cm+3. In 1951, the same workers prepared curium in
its elemental form for the first time. Sixteen isotopes of curium
are now known. The most stable, 247Cm, with a half-life
of 16 million years, is so short compared to the Earth’s age that
any primordial curium must have disappeared long ago from
the natural scene. Minute amounts of curium probably exist
in natural deposits of uranium, as a result of a sequence of
neutron captures and β decays sustained by the very low flux
of neutrons naturally present in uranium ores. The presence
of natural curium, however, has never been detected. 242Cm
and 244Cm are available in multigram quantities. 248Cm has
been produced only in milligram amounts. Curium is similar
in some regards to gadolinium, its rare-earth homolog, but it
has a more complex crystal structure. Curium is silver in color,
is chemically reactive, and is more electropositive than aluminum.
CmO2, Cm2O3, CmF3, CmF4, CmCl3, CmBr3, and CmI3
have been prepared. Most compounds of trivalent curium are
faintly yellow in color. 242Cm generates about three watts of
thermal energy per gram. This compares to one-half watt per
gram of 238Pu. This suggests use for curium as a power source.
244Cm is now offered for sale by the O.R.N.L. at $185/mg plus
packing charges. 248Cm is available at a cost of $160/μg, plus
packing charges, from the O.R.N.L. Curium absorbed into the
body accumulates in the bones, and is therefore very toxic as
its radiation destroys the red-cell forming mechanism. The
maximum permissible total body burden of 244Cm (soluble) in
a human being is 0.3 μCi (microcurie).
Hazard
Curium metal and its compounds are radioactive bone-seeking poisons that attack theskeletal system of humans and animals. Care must be used in handling them.
Check Digit Verification of cas no
The CAS Registry Mumber 7440-51-9 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, 5 and 1 respectively.
Calculate Digit Verification of CAS Registry Number 7440-51:
(6*7)+(5*4)+(4*4)+(3*0)+(2*5)+(1*1)=89
89 % 10 = 9
So 7440-51-9 is a valid CAS Registry Number.
InChI:InChI=1/Cm
