{"id":122,"date":"2020-04-08T15:06:09","date_gmt":"2020-04-08T15:06:09","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=122"},"modified":"2023-08-16T08:44:13","modified_gmt":"2023-08-16T08:44:13","slug":"cobalt","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/cobalt\/","title":{"rendered":"Cobalt (Co)"},"content":{"rendered":"\n

Cobalt is a chemical element with an atomic number of 127 in the periodic table of elements<\/a>. It occurs abundantly in Earth\u2019s crust, but mostly in a compound form. This strong ferromagnetic element is a member of the transition metals family in the periodic table. Having two valence electrons, cobalt is a relatively active but highly magnetic element, forming many compounds with other chemical elements.<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Cobalt<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
Symbol<\/td>Co<\/td><\/tr>
Name<\/td>Cobalt<\/td><\/tr>
Atomic number<\/td>27<\/td><\/tr>
Atomic weight<\/td>58.9332 g.mol-1<\/td><\/tr>
Group<\/td>8 (Transition metal)<\/td><\/tr>
Period<\/td>4<\/td><\/tr>
Color<\/td>A lustrous silvery-white metal with a bluish hue<\/td><\/tr>
Physical state<\/td>Solid at room temperature<\/td><\/tr>
Electronegativity<\/td>1.8<\/td><\/tr>
Density<\/td>8.9 g.cm-3 at 20\u00b0C<\/td><\/tr>
Melting point<\/td>1495 \u00b0C<\/td><\/tr>
Boiling point<\/td>2927 \u00b0C<\/td><\/tr>
Ionic radius<\/td>0.078 nm (+2) ; 0.063 nm (+3)<\/td><\/tr>
Isotopes<\/td>8 (1 stable isotope)<\/td><\/tr>
Most characteristic isotope<\/td>cobalt-60<\/td><\/tr>
Electronic shell<\/td>[Ar] 3d7 4s2<\/td><\/tr>
The energy of the first ionization<\/td>757 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>1666.3 kJ.mol-1<\/td><\/tr>
Discoverer<\/td>Georg Brandt<\/td><\/tr>
Year<\/td>1737<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
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With the periodic table symbol (Co), atomic number 27, atomic mass of 58.9332 g.mol<\/span>-1<\/span>, and electron configuration  [Ar] 3d<\/span>7<\/span> 4s<\/span>2<\/span>, cobalt reaches its boiling point at 2927 \u00b0C, while the melting point is achieved at 1495 \u00b0C. This brittle and strong ferromagnet retains its magnetism even at high temperatures, i.e. it has the highest <\/span>Curie point<\/span><\/i> of all metals in the periodic table of elements. <\/span><\/p>\n\n\n\n

Due to this, cobalt is one of the three naturally occurring magnetic metals (along with nickel<\/a> and iron<\/a>). This lustrous silvery-white metal is highly reactive with acids but non-reactive with H<\/span>2<\/span>O molecules. <\/span><\/p>\n\n\n\n

Having an electronegativity of 1.8 according to Pauling, +4 oxidation state, and atomic radius according to van der Waals of 0.125 nm, the electron configuration of this transition metal remains stable in contact with air. Cobalt is resistant to burning as a metal, though the same is not true for its powdery form.\u00a0<\/span><\/p>\n\n\n\n

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

The first known evidence of cobalt was found in the cultural remains of ancient Babylon and Egypt. These people have used cobalt as a source of blue dye for the decoration of pottery and glass. The Tang (600-900 AD) and Ming dynasties (1350-1650 AD) of ancient China are famous for their blue decorated <\/span>porcelain<\/span><\/a>. These civilizations used to obtain the rich blue pigment mainly from the cobalt salts. <\/span><\/p>\n\n\n\n

In 1739, Swedish chemist Georg Brandt (1694 – 1768) attempted an experiment with copper-resembling ore, i.e. <\/span>kobold<\/span><\/i>. He conducted this research in an effort to oppose the belief of the alchemists and prove that bismuth<\/a> and arsenic<\/a> do not produce the blue pigment. Brandt managed to isolate the pure elemental form of cobalt, i.e. the cobalt metal via the fire assay procedure.<\/span><\/p>\n\n\n\n

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

Brandt managed to isolate the pure elemental form of cobalt from the ore labeled by the German miners as \u2018kobold\u2019 – a medieval German word meaning \u2018goblin\u2019. The reason behind this uncommon name choice was the strong conviction and belief of the miners that goblins living in the Schneeberg Mountains had put a spell on this ore. This comes from the fact that the ore they were mining resembled natural copper<\/a> deposits, but they still couldn\u2019t exploit and separate any copper from it. <\/span><\/p>\n\n\n\n

When Brandt discovered the new element, he remembered the story and found it most suitable to name the element <\/span>cobalt<\/span><\/i>. He wrote about his newly discovered element under this name in his scientific research, published under the original title \u201c<\/span>Dissertatio de Semi-Metallis<\/span><\/i>\u201d.\u00a0<\/span><\/p>\n\n\n\n

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

In its elemental form, cobalt occurs in the core of Earth and the Sun, but in extremely small quantities. Cobalt is more frequently found as a part of compounds in nature. It can also be found as a trace element in humans, animals, seawater, and plants.<\/span><\/p>\n\n\n\n

Most commonly, this substance is nowadays obtained as a by-product in the mining of nickel and copper, i.e. from the nickel-copper sulfide deposits and the nickel-bearing laterites. The largest cobalt deposits in the United States are in Alaska, California, Idaho, Montana, North Carolina, Maine, Michigan, Minnesota, Missouri, New Mexico, Oregon, Pennsylvania, Puerto Rico, and Tennessee. <\/span><\/p>\n\n\n\n

The Democratic Republic of the Congo, Zambia, Finland, Azerbaijan, Kazakhstan, China, and Russia, count among the world\u2019s largest cobalt producing countries. They also represent locations that have the highest quantities of cobalt ores, such as cobaltite, skutterudite, erythrite, and glaucodot.\u00a0<\/span><\/p>\n\n\n\n

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

Due to its strong magnetic, thermal, and anti-corrosive properties, the use of cobalt has various applications in everyday life. This transition metal can be found in many industries, production processes, and products we frequently use:<\/span><\/p>\n\n\n\n