{"id":256,"date":"2020-04-09T10:10:47","date_gmt":"2020-04-09T10:10:47","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=256"},"modified":"2023-08-15T13:57:58","modified_gmt":"2023-08-15T13:57:58","slug":"uranium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/uranium\/","title":{"rendered":"Uranium (U)"},"content":{"rendered":"\n

Uranium is a chemical element with the atomic number 92 in the periodic table. This substance makes up about two parts per million of Earth’s crust. Uranium in the layers of Earth is as common as the elements tin, tungsten<\/a>, and molybdenum<\/a>.<\/span><\/p>\n\n\n\n

As a member of the actinide series of periodic table elements, this naturally occurring radioactive element has been used as an abundant source of nuclear energy and in the making of atomic bombs for over 60 years. Uranium is also applied in nanotechnology, virology, cancer research, radiometric dating, materials science, etc.\u00a0<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Uranium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
Symbol<\/td>U<\/td><\/tr>
Atomic number<\/td>92<\/td><\/tr>
Atomic weight (mass)<\/td>238.03 g.mol-1<\/td><\/tr>
Group (number)<\/td>Actinides<\/td><\/tr>
Period<\/td>7 (f-block)<\/td><\/tr>
Color<\/td>A silvery-white metallic element<\/td><\/tr>
Physical state<\/td>Solid at room temperature<\/td><\/tr>
Half-life<\/td>From 0.52(+0.95\u22120.21) milliseconds to 4.4683\u00d7109 years<\/td><\/tr>
Electronegativity according to Pauling<\/td>1.7<\/td><\/tr>
Density<\/td>18.95 g.cm-3 at 20\u00b0C<\/td><\/tr>
Melting point<\/td>1135\u00b0C, 2075\u00b0F, 1408 K<\/td><\/tr>
Boiling point<\/td>4131\u00b0C, 7468\u00b0F, 4404 K<\/td><\/tr>
Van der Waals radius<\/td>0.121 nm<\/td><\/tr>
Ionic radius<\/td>0.103 nm (+3); 0.093 nm (+4)<\/td><\/tr>
Isotopes<\/td>29<\/td><\/tr>
Most characteristic isotope<\/td>234U, 235U, 238U<\/td><\/tr>
Electronic shell<\/td>[Rn] 5f3 6d1 7s2<\/td><\/tr>
The energy of the first ionization<\/td>6.1941 eV<\/td><\/tr>
The energy of the second ionization<\/td>N\/A<\/td><\/tr>
Discovery date<\/td>In 1789 by Martin Klaproth<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

With the periodic table symbol U, atomic number 92, atomic mass of 238.03 g.mol<\/span>-1<\/span>, and electron configuration X, uranium is a dense, hard, ductile, and malleable sivery-white radioactive element. This metallic substance reaches its boiling point at 4131\u00b0C, 7468\u00b0F, 4404 K, while the melting point is achieved at 1135\u00b0C, 2075\u00b0F, 1408 K. <\/span><\/p>\n\n\n\n

A uranium atom has 92 protons and 92 electrons. Six of them are valence electrons. Uranium is a member of the actinides group in the periodic table with an electronegativity of 1.7 according to Pauling, whereas the atomic radius according to van der Waals is 0.121 nm. Also, this chemical is an electropositive element with an orthorhombic structure. When exposed to air, it quickly tarnishes.<\/span><\/p>\n\n\n\n

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

Martin Heinrich Klaproth (<\/span>1743 \u2013 1817) was a German apothecary and chemist. Interested in the structure of minerals, in 1789 his scientific curiosity was triggered by a sample of the mineral pitchblende (uranium dioxide or uranium(IV) oxide (UO<\/span>2<\/span>). Convinced that he had a zinc<\/a>\/iron<\/a> ore in his hands, Klaproth attempted to dissolve the pitchblende in nitric acid. In the next step, he added potash (an alkaline potassium compound) to the substance in an effort to produce yellow precipitation. <\/span><\/p>\n\n\n\n

However, the result was not anticipated or familiar to Klaproth. Because the potash dissolved the yellow precipitate, the German chemist concluded that the substance in front of him is, in fact, a new chemical element.<\/span><\/p>\n\n\n\n

In 1841, the French chemist Eug\u00e8ne-Melchior P\u00e9ligot (1811-1890) succeeded in isolating the first sample of uranium metal by conducting a reduction of uranium tetrachloride (UCl4) with potassium.\u00a0<\/span><\/p>\n\n\n\n

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The Discovery of Radiation <\/span><\/h3>\n\n\n\n

Studying phosphorescence and x-ray properties, the French physicist Henri Becquerel had serendipitously discovered the phenomenon of <\/span>radiation<\/span><\/a> in 1896. Namely, by exposing uranium-based crystals wrapped in thick black paper to sunlight, he observed a shadow on the photographic plate where the crystals were positioned that had pierced through the paper. <\/span><\/p>\n\n\n\n

The discovery of this French scientist further led the way of Marie and Pierre Curie to the discovery of the radioactive elements polonium<\/a> and radium<\/a>. The Curies were also the first scientists who had coined and used the term <\/span>radioactivity<\/span><\/i>.\u00a0<\/span><\/p>\n\n\n\n

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

Since Martin Klaproth discovered uranium by an unexpected chemical reaction, he named the new element \u2018<\/span>uranium<\/span><\/i>\u2019 after the newly found planet Uranus. In astronomy, the seventh planet from the Sun was named Uranus after the Greek God of the Sky, and represents sudden and unpredictable changes.\u00a0<\/span><\/p>\n\n\n\n

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

About 6.6 billion years ago, uranium was created in the Universe by supernova explosions. With an abundance of over 4 parts per million in Earth\u2019s crust, uranium naturally occurs in many minerals. Low concentrations of uranium can be traced in water, soil, rocks, and air. <\/span><\/p>\n\n\n\n

Nowadays, element 92 is primarily obtained from the minerals pitchblende, uranitide, torbernite, autunite, torbernite, and carnotite. It\u2019s mainly isolated by an ion-exchange technique, in heap leach facilities, in situ recovery facilities, as well as in uranium mills. <\/span><\/p>\n\n\n\n

Kazakhstan, Canada, Australia, Niger, Namibia, Russia, USA, Uzbekistan, United States, China, South Africa and Germany are among the world\u2019s largest producers of uranium.\u00a0<\/span><\/p>\n\n\n\n

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List of Uranium Minerals<\/span><\/h3>\n\n\n\n

The wast list of minerals in which uranium occurs contains the following items:<\/span><\/p>\n\n\n\n