{"id":44,"date":"2020-04-08T14:58:20","date_gmt":"2020-04-08T14:58:20","guid":{"rendered":"https:\/\/thechemicalelements.com\/?page_id=44"},"modified":"2023-08-16T10:34:43","modified_gmt":"2023-08-16T10:34:43","slug":"barium","status":"publish","type":"post","link":"https:\/\/thechemicalelements.com\/barium\/","title":{"rendered":"Barium (Ba)"},"content":{"rendered":"\n

Barium is the fifth chemical element in the periodic table of elements<\/a> with the atomic number 56. Being a member of the alkaline earth metals family, this soft metal is divalent, electropositive, and reactive, and supports the formation of many compounds with other chemical elements, especially carbon<\/a>, oxygen, and sulphur. Due to its high reactivity, barium cannot be found in the Earth\u2019s crust in its elemental form. It mainly appears as a part of compounds.<\/span><\/p>\n\n\n\n

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Chemical and Physical Properties of Barium<\/span><\/h3>\n\n\n\n
Property<\/strong><\/td>Value<\/strong><\/td><\/tr>
The symbol in the periodic table of elements<\/td>Ba<\/td><\/tr>
Atomic number<\/td>56<\/td><\/tr>
Atomic weight (mass)<\/td>137.33 g.mol-1<\/td><\/tr>
Group number<\/td>2 (II a)<\/td><\/tr>
Period<\/td>6<\/td><\/tr>
Color<\/td>Silvery-white metal<\/td><\/tr>
Physical state<\/td>Soft alkaline earth metal at room temperature<\/td><\/tr>
Half-life<\/td>N\/A<\/td><\/tr>
Electronegativity according to Pauling<\/td>0.9 (\u03c7 = 0.89)<\/td><\/tr>
Density<\/td>3.5 g.cm-3 at 20\u00b0C<\/td><\/tr>
Melting point<\/td>725 \u00b0C<\/td><\/tr>
Boiling point<\/td>1640 \u00b0C<\/td><\/tr>
Van der Waals radius<\/td>0.222 nm<\/td><\/tr>
Ionic radius<\/td>0.135<\/td><\/tr>
Isotopes<\/td>16 (6 stable isotopes)<\/td><\/tr>
Most characteristic isotope<\/td>130-138Ba<\/td><\/tr>
Electronic shell<\/td>[ Xe ] 6s2<\/td><\/tr>
The energy of the first ionization<\/td>502.7 kJ.mol-1<\/td><\/tr>
The energy of the second ionization<\/td>965 kJ.mol-1<\/td><\/tr>
Discovery date<\/td>In 1808 by Sir Humphry Davy<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

In the periodic table, this dense and reactive chemical element is labeled with the symbol (Ba) and exhibits an oxidation state of +2. With the atomic number 56, atomic mass of 137.33 g.mol -1, and electronic configuration [ Xe ] 6s<\/span>2<\/span>, barium is a soft and easily breakable metal with Mohs hardness of 1.25. <\/span><\/p>\n\n\n\n

It reaches its boiling point at 1640 \u00b0C, while the melting point is achieved at 725 \u00b0C. When barium is exposed to heat, it gives away a pale yellow-green flame. <\/span><\/p>\n\n\n\n

This member of the alkaline earth metals family is an excellent conductor of electricity with an electronegativity of 0.9 according to Pauling, whereas the atomic radius according to van der Waals is 0.222 nm.    <\/span><\/p>\n\n\n\n

Even though barium<\/a> shares a large percent of the chemical properties with magnesium<\/a>, strontium<\/a>, and calcium<\/a>, it\u2019s far more reactive than them. Barium\u2019s reactivity with oxygen<\/a>, halogens<\/a>, acids, and many other non-metal elements<\/a> is so high that it must be kept in petroleum or kerosene in order to prevent uncontrolled chemical reactions.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/span><\/p>\n\n\n\n

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How Was Barium Discovered?<\/span><\/h3>\n\n\n\n

The story of barium begins in 1600, when Vincenzo Casciarolo (Bologna, 1571 \u2013 Bologna, 1624, an Italian alchemist and shoemaker) tried to convert a stone to gold<\/a>. Little did he know that that \u2018stone\u2019 was actually a barium sulfate (BaSO<\/span>4<\/span>). <\/span><\/p>\n\n\n\n

By trying to reduce this chemical compound of barium with coal, Casciarolo succeeded in producing barium sulphide with luminescent properties in his small and improvised lab near Bologna, Italy. Namely, he\u2019d exposed those \u2018stone pebbles\u2019 to sunshine, and at night, they had started glowing in the dark. <\/span><\/p>\n\n\n\n

By this <\/span>mishap<\/span><\/i>, this amateur chemist from Italy made great strides toward discovering  both barium and luminescence. This was also the first finding in the world of chemistry reporting an example of phosphor. Since Casciarolo failed to discover the \u2018philosopher\u2019s stone\u2019 in his attempt to make gold out of the pebbles of an impure barium sulphate, his experiment was labeled as the \u2018Bologna stone\u2019, which is synonymous with the curiosity of this Italian alchemist. <\/span><\/p>\n\n\n\n

Many years later, in 1774, barium was recognised as a new chemical element. The Swedish scientist Carl W. Scheele was performing research on magnesium oxide which led him to the new discovery of barium oxide. In 1784, the English naturalist William Withering discovered the witherite (barium carbonate, BaCO3) after multiple experiments conducted on the heavy ore of \u201cterra ponderosa\u201d, excavated in Cumberland, England. <\/span><\/p>\n\n\n\n

He then proved that barite and the mineral do not have identical chemical formulas and represent two separate minerals. <\/span><\/p>\n\n\n\n

However, the development of electrolysis in 1808 as one of the main techniques in chemical experiments provided the necessary means for isolating barium in its pure form. <\/span><\/p>\n\n\n\n

Following the scientific work of the Swedish chemist Jacob Berzelius and his experience with electrolysis, the English chemist Sir Humphry Davy recreated the experiment in London and managed to decompose barium sulfate by conducting electrolysis of molten baryta (BaO). <\/span><\/p>\n\n\n\n

In this way, he isolated pure barium metal at the Royal Institution in London. In a similar way, Davy also successfully isolated strontium.\u00a0<\/span><\/p>\n\n\n\n

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How Did Barium Get Its Name?<\/span><\/h3>\n\n\n\n

When Scheele discovered the new element in 1774, he named it \u2018terra ponderosa\u2019, which in Latin means \u2018heavy earth\u2019. Later, the Greek word \u201c\u03b2\u03b1\u03c1\u03cd\u03c2\u201d (barys), meaning “heavy”, was adopted for barium in order to depict its high atomic mass and density.<\/span><\/p>\n\n\n\n

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Where Can You Find Barium?<\/span><\/h3>\n\n\n\n

With a concentration of approximately 0.05% in the Earth’s crust, barium counts as the 14<\/span>th<\/span> most abundant substance of the periodic system of elements. Most commonly, this soft metal can be found in underground ore deposits of the mineral barite (barium sulphate [<\/span>BaSO\u2084]<\/span>) and witherite (barium carbonate [BaCO\u2083]). <\/span><\/p>\n\n\n\n

They are located in hydrothermal and mesothermal metal ore veins, as well as in the sedimentary rock layers and volcanic rocks (basalts). Barium can also be produced by electrolysis of barium chloride – BaCl<\/span>2.<\/span><\/p>\n\n\n\n

Concentrations of barium can also be found in fish, some types of nuts, and seaweed. The world\u2019s major barium ore mines are located in: <\/span><\/p>\n\n\n\n