Barium: The Element

Barium is a heavy chemical element, having the symbol Ba and atomic number 56. This soft silvery alkaline earth metal is never found in its purest form in nature, mainly because of its high reactivity to air. It is kept either in petroleum based fluids or oxygen free liquids, to restrain it from being oxidized. Barium peroxide, barium chloride, chlorate, sulfate etc are some of the major compounds of barium. Barium sulphate and barium carbonate are the most common naturally occurring minerals.

The word barium is derived from the Greek word, Bary, meaning heavy. It was identified by a Swedish pharmaceutical chemist, Carl Scheele, in 1774, and scientifically obtained by the British chemist, Sir Humphry Davy, in 1808.

Barium is found in mineral barite, that is crystallized barium sulphate. Barite being insoluble, cannot be used directly to produce other barium compounds, therefore, the ore is heated with carbon to reduce the content of barium sulphide in it. Various compounds of barium are formed by hydrolyzing or reacting it with other acids. These barium compounds include barium chloride, barium carbonate and barium nitrate.

Characteristics of Barium

• It is difficult to obtain barium in its purest form because of its tendency to oxidize in air.
• Barium, though chemically similar to calcium, is much more reactive than calcium.
• It is the 14th most abundant element on the planet.
• It has a boiling point of 1640 degree Celsius, and a melting point of 725 degree Celsius.
• It oxidizes readily when exposed to air, and ignites spontaneously when exposed to moist air.
• Barium reacts with water or alcohol to produce hydrogen.
• If burned in presence of air or oxygen, it produces barium oxide and peroxide.
• Its compounds have high specific gravity of 3.5 at 20 degree Celsius.
• All the compounds of barium, which are soluble in water or acid are poisonous.

Uses of Barium

• Barium compounds are used extensively in petroleum industry.
• Barite is used as a drilling fluid for drilling boreholes into the earth's crust.
• Barium enema is used as a radiocontrast agent in x-ray imaging of the digestive system.
• Coating the electrodes of fluorescent lamps with barium oxide eases the release of electrons.
• This metal is used to take out the last traces of oxygen in vacuum tubes.
• Barium carbonate, a compound of barium, is used in cement, bricks, glass making and rat poison.
• Barite is an important component of the rubber production industry.
• The green color that appears during the display of fireworks is attributed to the presence of barium nitrate in them.
• When welding rail track together, barium peroxide, a compound of barium, is used as a catalyst to initiate an aluminothermic reaction.
• Barium floride, a chemical compound of barium and fluorine, is used to make optics in infra red applications.
• Barium is an important component of high temperature yttrium barium copper oxide superconductors.

Effects of Barium on Humans
When taken in low doses, barium works as a muscle stimulant. However, higher doses block the potassium ion channels, essential for the proper functioning of nervous system, thus, triggering an adverse effect in the nervous system, causing cardiac problems, weakness, paralysis and anxiety. It is possible to take barium orally, because like other heavy metals, it doesn't accumulate within the bodies of living organisms. Being highly insoluble, it is easily eliminated through the digestive tract. However, if inhaled, in the form of dust or gas, it can get accumulated in the lungs, and cause baritosis, a benign type of pneumoconiosis.

Since its discovery in the first half of the 19th century, barium has become an important constituent of most of the industries today. It has become very difficult to substitute this metal with an equally dominant counterpart.