{"id":250,"date":"2020-04-09T10:10:02","date_gmt":"2020-04-09T10:10:02","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=250"},"modified":"2023-08-15T14:06:08","modified_gmt":"2023-08-15T14:06:08","slug":"plutonium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/plutonium\/","title":{"rendered":"Plutonium (Pu)"},"content":{"rendered":"\n

Plutonium is a chemical element with the atomic number 94 in the periodic table. Despite being a synthetically produced substance, some trace amounts of plutonium may occur naturally in combination with other chemical elements. This chemical is discovered as the second synthetic transuranium element of the actinide series of the periodic table.<\/span><\/p>\n\n\n\n

Being a member of the actinides family of periodic table elements, this highly radioactive transuranic metallic element is a divalent substance. Along with uranium<\/a>-235, plutonium-239 is one of the two fissile materials that are popularly used in the construction of nuclear weapons and atomic bombs, as well as for the production of energy in nuclear power plants. <\/span><\/p>\n\n\n\n

Any exposure to any form and quantity of plutonium\u2019s radioactivity is extremely dangerous to human health, all living organisms, and environmental systems.\u00a0<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Plutonium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
Symbol<\/td>Pu<\/td><\/tr>
Atomic number<\/td>94<\/td><\/tr>
Atomic weight (mass)<\/td>(244) g.mol-1<\/td><\/tr>
Group (number)<\/td>Actinides<\/td><\/tr>
Period<\/td>7 (f-block)<\/td><\/tr>
Color<\/td>A silvery-white radioactive metal<\/td><\/tr>
Physical state<\/td>Solid at room temperature<\/td><\/tr>
Half-life<\/td>From 1.1(+20\u22125) seconds to 80.8 million years<\/td><\/tr>
Electronegativity according to Pauling<\/td>Unknown<\/td><\/tr>
Density<\/td>19.84 g.cm-3 at 20\u00b0C<\/td><\/tr>
Melting point<\/td>640\u00b0C, 1184\u00b0F, 913 K<\/td><\/tr>
Boiling point<\/td>3228\u00b0C, 5842\u00b0F, 3501 K<\/td><\/tr>
Van der Waals radius<\/td>Unknown<\/td><\/tr>
Ionic radius<\/td>Unknown<\/td><\/tr>
Isotopes<\/td>20<\/td><\/tr>
Most characteristic isotope<\/td>238Pu, 239Pu, 240Pu<\/td><\/tr>
Electronic shell<\/td>[Rn] 5f6 7s2<\/td><\/tr>
The energy of the first ionization<\/td>558.6 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>N\/A<\/td><\/tr>
Discovery date<\/td>In 1940-1941 by Glenn Seaborg and colleagues<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

With the periodic table symbol Pu, atomic number 94, atomic mass of (244) g.mol<\/span>-1<\/span>, and electron configuration [Rn] 5f<\/span>6<\/span> 7s<\/span>2<\/span>, plutonium is a synthetically produced silvery-white radioactive metal. It reaches its boiling point at 3228\u00b0C, 5842\u00b0F, 3501 K, while the melting point is reached at 640\u00b0C, 1184\u00b0F, 913 K. <\/span><\/p>\n\n\n\n

Having an atomic number greater than 92, this man-made radioactive substance belongs to the class of transuranium elements. Unlike other chemical elements, the density of plutonium increases when it\u2019s exposed to high temperatures. In addition, the electronegativity according to Pauling of this member of the actinides family of elements is unknown, as well as the atomic radius according to van der Waals.<\/span><\/p>\n\n\n\n

Plutonium occurs in several allotropes which differ in their crystal structure and density. Normally, there are typically six plutonium allotropes. When exposed to high temperatures, plutonium forms a seventh (zeta, \u03b6) allotrope which is widely different from all other forms of this chemical element. <\/span><\/p>\n\n\n\n

This chemical element has a monoclinic crystal structure and possesses strong paramagnetic properties, but has poor thermal and electrical conductivity. When exposed to air, plutonium metal oxidizes with dull gray, yellow, or olive green tarnish.\u00a0<\/span><\/p>\n\n\n\n

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How Was Plutonium Discovered?<\/span><\/h2>\n\n\n\n

Plutonium was discovered in 1940 by an American team of renewed scientists which included Edwin M. McMillan, J. W. Kennedy, and A. C. Wahl. Led by Dr. Glenn T. Seaborg (1912\u20131999). The team of discoverers performed their revolutionary experiment at the University of California, Berkeley in the later part of 1940.<\/span><\/p>\n\n\n\n

The story of plutonium\u2019s discovery begins in 1939, after the announcement of the nuclear fission phenomenon by the scientists Otto Hahn and Fritz Strassmann. A year later, the American physicist and Nobel laureate Edwin M. McMillan (1907 \u2013 1991) confirmed this phenomenon in a joint effort with the American physicist, scientific editor, and science writer Philip Abelson (1913 \u2013 2004). <\/span><\/p>\n\n\n\n

By using the small 27-inch cyclotron at Berkeley laboratory, McMillan and Abelson bombarded uranium-238 isotopes with neutrons produced from deuterons. This chemical reaction produced a decay chain in which the resulting uranium-238 decayed to neptunium<\/a>-238, which underwent a beta decay to form plutonium (<\/span>94<\/span>Pu). Unfortunately, McMillan wasn’t able to finish the experiment and prove that it\u2019s fissionable because WWII was raging, and he was asked to help with the production of nuclear bombs at the <\/span>Los Alamos National Laboratory<\/span><\/a>, United States.   <\/span><\/p>\n\n\n\n

At that point, Dr. Seaborg and his colleagues took over and continued with McMillan\u2019s project. Shortly after they commenced where McMillan had stopped, the team of scientists observed that slow neutrons cause plutonium-239 to undergo fission, continuing the nuclear chain reaction by releasing more and more neutrons. This revolutionary discovery meant that plutonium can be used as a new material from which a nuclear bomb could be constructed. <\/span><\/p>\n\n\n\n

The first visible quantity of plutonium [a microgram of pure plutonium-239 compound (plutonium IV iodate)] was synthetically produced in 1942 by Burris Cunningham and Louis Werner at the Metallurgical Laboratory of the University of Chicago. <\/span><\/p>\n\n\n\n

In 1943, the first sample of plutonium metal was produced by reducing plutonium trifluoride with lithium<\/a>.\u00a0<\/span><\/p>\n\n\n\n

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The Manhattan Project<\/span><\/h3>\n\n\n\n

After the team of researchers discovered plutonium and observed it could sustain a nuclear chain reaction, Seaborg secretly wrote to President Roosevelt, informing him about this new substance that possesses the potential to be a powerful source of nuclear energy. <\/span><\/p>\n\n\n\n

Realizing the advantage of this substance as a nuclear weapon in the war, a secret project codenamed the <\/span>Manhattan Engineering District<\/span><\/a> was established. The aim of the Manhattan Project was to produce a nuclear bomb.\u00a0<\/span><\/p>\n\n\n\n

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How Did Plutonium Get Its Name?<\/span><\/h2>\n\n\n\n

Element 94 was named after<\/a> the planet Pluto<\/a>. The naming of the new chemical element <\/span>plutonium<\/span><\/i> after a planet continues the pattern started by Martin Klaproth, who named the element <\/span>uranium<\/span><\/i> after the planet Uranus<\/a>.\u00a0<\/span><\/p>\n\n\n\n

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Where Can You Find Plutonium?<\/span><\/h2>\n\n\n\n

Plutonium is a byproduct of the nuclear power industry made in various types of nuclear reactors. However, trace quantities of plutonium may occur in nature, mostly combined with other elements. Also, some plutonium quantities can be found in natural uranium ores.<\/span><\/p>\n\n\n\n

Most of this highly radioactive chemical element is commercially produced in power reactors used for research or plutonium production reactors. The latter ones are also called <\/span>breeder reactors<\/span><\/i> because they produce more plutonium than they consume fuel.<\/span><\/p>\n\n\n\n

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Plutonium in Everyday Life<\/span><\/h2>\n\n\n\n

In addition to being used as the main source of energy in nuclear reactors and weapons, this transuranic element has some practical everyday uses as well:<\/span><\/p>\n\n\n\n