It also packs a huge nuclear punch when it's in the right sort of warhead and also has the power to be a super conductor. The only problem is its radio active and that means that when it decays it tends to fall apart. Plutonium's often billed as the 'most toxic substance known to man'. Just the word plutonium instils a dread in people's minds - And it's the early history of plutonium that established its dark side - and it's a reputation that's been hard to shake-off since.
Glenn Seaborg discovered plutonium at Berkeley in , and in the following spring, when it was found that it could sustain a nuclear chain reaction, he secretly wrote to President Roosevelt, to inform him of that this substance had the potential to be a powerful source of nuclear energy.
And from that moment the race was on to produce significant amounts to supply a secret project codenamed the Manhattan Engineering District, the goal of which was to produce a nuclear bomb.
Anyone familiar with the iconic image of the mushroom cloud understands the tremendous explosive power of a correctly controlled detonation of plutonium. The energy density is mind-boggling: a sphere of metal 10 cm in diameter and weighing just 8 Kg is enough to produce an explosion at least as big as the one that devastated Nagasaki in But apart from military uses like this, plutonium also has one of the richest chemistries of any element.
There are six different forms of plutonium, known as allotropes, that all exist at different temperatures and behave differently.
At room temperature, for instance, the plutonium is very brittle, but heated to around Celsius is transforms to a much more malleable metal. Scientists have found that they can mimic this effect by adding a small amount of gallium, which gives the room temperature metal similar properties to its higher-temperature counterpart, and this makes it much easier to work with.
Mixing plutonium with other metals can also produce substances with other interesting properties. For instance, adding some cobalt and gallium can produce a material that behaves as a super-conductor at low temperatures. Its electrons link up into a close-knit arrangement called Cooper pairs, which allow electricity to flow freely with no resistance.
But unfortunately this arrangement doesn't last very long. Because plutonium self destructs, undergoing radioactive decay by spitting out a highly energetic alpha-particle to produce Uranium But as the alpha-particle leaves it causes the uranium nucleus to recoil like a gun that's just been fired, and this damages the structure of the material, disrupting the paired electrons and slowly destroying the superconductivity.
So in this sense plutonium is its own worst enemy. Its radioactivity means that it's very difficult to exploit the richness of its chemistry in many compounds, and as its reputation precedes it, plutonium would also have trouble gaining acceptance as a technological material. Nowadays it's been replaced by better batteries, but it's still popular with space scientists who use it to power probes sent to explore distant planets far from the Sun, like Cassini, that was sent to Saturn, and New Horizons, which is on its way to Pluto.
Plutonium's in a part of the periodic table called the actinide series alongside its neighbours thorium and protoactinium. Seaborg christened the actinides, rearranging the periodic table in the process, on the basis of the unusual arrangements of their electrons, which give these substances unusual magnetic properties, as well as the ability to have multiple oxidation states.
Plutonium, for instance, has five, giving it the ability to form an unusually wide range of compounds that scientists are only just beginning to get to grips with. Some say that plutonium's an evil element created by man, but it's actually a natural element produced by a process known as nucleosynthesis, which takes place in supernova explosions, when dying stars blow themselves to pieces.
There isn't much of it on the earth naturally, because the majority of its isotopes have such short half-lives. And in the 4. What there is mostly comes from reactors and nuclear tests. There are severe hazards associated with plutonium, but as with most dangerous materials, these can be mitigated by careful handling and rigorous safeguards. But whatever you think about plutonium, its history, however chequered, has revealed some fascinating chemistry.
Although the mushroom cloud remains its best-known image. Ian Farnan, unpacking Plutonium. Next time on Chemistry in its Element the toxic chemical that saves thousands of lives every year. In his list of the then known elements, Lavoisier included the term azote meaning the absence of life, but the compound used to explosively fill car air bags with gas is sodium azide, a compound of just Sodium and Nitrogen.
When triggered this compound explosively decomposes freeing the Nitrogen gas, which inflates the bags. Far from destroying life, this azotic compound has been responsible for saving thousands. Peter Wothers talking nitrogen on what promises to be an explosive edition of Chemistry in its element next week. I'm Chris Smith, thank you for listening, see you next time.
Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists. There's more information and other episodes of Chemistry in its element on our website at chemistryworld. Click here to view videos about Plutonium. View videos about. Help Text. Learn Chemistry : Your single route to hundreds of free-to-access chemistry teaching resources.
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Periodic Table of Videos , accessed December Podcasts Produced by The Naked Scientists. Download our free Periodic Table app for mobile phones and tablets. During Seaborg's time in Chicago, he developed the "actinide concept", which essentially postulated the existence of the 5f row of elements below the lanthanides in the periodic table. The concept was verified by the preferred oxidation states of elements 95 and 96, americium and curium, identified by his team in Seaborg patented both of them the only chemical elements ever to be patented , which turned out to be a commercial success since small amounts of americium are used in household smoke detectors.
His team synthesized the next six transuranium elements between and In , Glenn Seaborg received the Nobel Prize in Chemistry together with Edwin Mattison McMillan "for their discoveries in the chemistry of the transuranium elements". Apart from the Nobel Prize, he received dozens of honorary doctorates and numerous other awards. Element was named seaborgium in his honor, even though naming an element after a living scientist was considered unusual and caused some controversy.
During his tenure, which spanned three US presidencies, he had significant roles in both nuclear test ban treaties and non-proliferation treaties. Besides being naturally present in very small amounts, plutonium may also enter the environment from releases of nuclear reactors, weapons production plants, and research facilities. A major source of plutonium release is nuclear weapons testing.
Annual world production of plutonium is probably in excess of 50 tonnes and there may be more than 1. Plutonium is sometimes described in media reports as the most toxic substance known to man, although there is general agreement among experts in the field that this is incorrect.
As of , there has yet to be a single human death officially attributed to plutonium exposure. Naturally-occurring radium is about times more radiotoxic than plutonium, and some organic toxins like Botulism toxin are billions of times more toxic than plutonium.
The alpha radiation it emits does not penetrate the skin, but can irradiate internal organs when plutonium is inhaled or ingested. Extremely small particles of plutonium on the order of micrograms can cause lung cancer if inhaled into the lungs.
Considerably larger amounts may cause acute radiation poisoning and death if ingested or inhaled; however, so far, no human is known to have died because of inhaling or ingesting plutonium and many people have measurable amounts of plutonium in their bodies. Plutonium is a dangerous substance that has been used in explosives for a long time. It is released into the atmosphere primarily by atmospheric testing of nuclear weapons and by accidents at weapon production sites.
When plutonium is released into the atmosphere it will fall back onto earth eventually and end up in soils. Exposure of humans to plutonium is not likely, but sometimes it takes place as a result of accidental releases during use, transport or disposal.
Because plutonium has no gamma radiation, health effects are not likely to occur while working with plutonium, unless it is breathed in or swallowed somehow. Freshly prepared plutonium metal has a silvery bright color but takes on a dull gray, yellow, or olive green tarnish when oxidized in air. The metal quickly dissolves in concentrated mineral acids. A large piece of plutonium feels warm to the touch because of the energy given off by alpha decay; larger pieces can produce enough heat to boil water.
At room temperature alpha-form plutonium the most common form is as hard and brittle as cast iron. It can be alloyed with other metals to form the room-temperature stabilized delta form, which is soft and ductile. Unlike most metals, plutonium is not a good conductor of heat or electricity. It has a low melting point and an unusually high boiling point. Plutonium can form alloys and intermediate compounds with most other metals, and compounds with a variety of other elements.
Some alloys have superconductive abilities and others are used to make nuclear fuel pellets. Its compounds come in a variety of colors, depending on the oxidation state and how complex various ligands are.
In aqueous solution there are five valance ionic states. Plutonium, along with all of the other transuranium elements, is a radiological hazard and must be handled with specialized equipment and precautions. Animal studies have found that a few milligrams of plutonium per kilogram of tissue are lethal.
Plutonium generally isn't found in nature. Trace elements of plutonium are found in naturally occurring uranium ores. Here, it is formed in a way similar to neptunium: by irradiation of natural uranium with neutrons followed by beta decay.
Primarily, however, plutonium is a byproduct of the nuclear power industry.
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