Element Barium (Ba), Group 2, Atomic Number 56, s-block, Mass 137.327. Sources, facts, uses, scarcity (SRI), podcasts, alchemical symbols, videos and images. Barium: biological data. Human abundance by weight: 300 ppb by weight; Barium has no biological role. The British Pharmaceutical Codex from 1907 indicates that barium chloride 'barii chloridum', BaCl 2.2H 2 O has a stimulant action on the heart and other muscles.It was said that it 'raises blood pressure by constricting the vessels and tends to empty the intestines, bladder, and gall bladder'.
- Barium(2+) is a barium cation, a divalent metal cation and a monoatomic dication. It has a role as a cofactor.
- The atomic number of barium is 56. It has naturally occurring isotopes with mass numbers of 130, 132, 134, 135, 136, 137, and 138. How many subatomic particles does barium have?
- Given an atomic number (Z) and mass number (A), you can find the number of protons, neutrons, and electrons in a neutral atom. For example, a lithium atom (Z=3, A=7 amu) contains three protons (found from Z), three electrons (as the number of protons is equal to the number of electrons in an atom), and four neutrons (7 – 3 = 4).
Barium is a chemical element with symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element
Discovery and History
In 1600, Vincenzo Casciarolo found unusual pebbles that were when exposed to heat would shine during night, named barite (Barium Sulfate BaSO4) [1]. Barium was identified as a new element in 1774 but not isolated in its pure form via electrolysis in 1808. The name barium have been derived from the Greek word barys that mean heavy.
Barium
| Periodic Table Classification | Group 2 Period 6 |
|---|---|
| State at 20C | Solid |
| Color | Silvery gray |
| Electron Configuration | [Xe] 6s2 |
| Electron Number | 56 |
| Proton Number | 56 |
| Electron Shell | 2, 8, 18, 18, 8, 2 |
| Density | 3.59 g.cm-3 at 20°C |
| Atomic number | 56 |
| Atomic Mass | 137.33 g.mol -1 |
| Electronegativity according to Pauling | 0.89 |
Occurrence
Barium is 14th most abundant element in earth crust. Its abundance is estimated about 0.05%. in nature, barium mostly occurs in combination with sulfur, oxygen and carbon. The most common source of barium is barite and witherite. Witherite ore containing barium carbonate BaCO3. The world’s major sources of barium ores are UK, China, Czech Republic, India, Morocco, the United States, Turkey, and Italy [2]. High amounts of barium are also found in soils and in plants, fish, seaweeds, and in nuts [3]. The barium mineral benitoite, occurs as a very rare blue fluorescent gemstone, and is considered as the official gem stone of California. Various anthropogenic activities have led to increased concentration of barium in the environment, including soil, water and air. Such activities include mining, oil combustion and coal combustion. The major ore of barium that are widely used for the extraction of barium is barite.
Physical properties
Pure barium is a silvery-white shiny malleable metal. It is comparatively dense and reactive alkaline earth metal. It has a melting point of about 725°C and a boiling point of about 1,640°C. Its density is 3.6 grams per cubic centimeter. When heated, barium compounds give off a pale yellow-green flame. [4] Barium has specific weight and good electrical conductivity. The atomic number of barium is 56 and atomic weight of 137.327 and belong to Group 2 periodic table.
Chemical properties
Barium chemically resembles, magnesium calcium and strontium but is more reactive. Reaction with chalcogens are highly exothermic. It combines easily with oxygen, the halogens, and other non-metals also reacts with water and most acids. It is so reactive that it must be stored under kerosene, petroleum, or some other oily liquid to prevent it from reacting with oxygen and moisture in the air. In alkaline family radium is more reactive. [5] Barium reacts with ammonia form complexes such as Ba (NH3)6. Barium combines with metals such as aluminum, zinc, lead and zinc forming alloys. When reacted with non-metals barium form poisonous compounds.
Compounds
Barium salts are white when solids and colorless when dissolved. They are denser than strontium or calcium analogs except for halides. Barium hydroxide unlike calcium hydroxide absorbs little CO2 in aqueous solution insensitive to atmospheric fluctuation. Volatile barium compound burns with a green to pale green flame.
Uses and Significance
- Used to remove unwanted gases from vacuum tubes such as TV pictures tubes.
- Barium sulfate is important in petroleum industry as drilling fluids in oil and gas wells.
- It is widely used in making barium-nickel alloys in spark-plug electrodes.
- It is used in making fluorescent lamps.
- Barium is used in making drilling mud, that is efficiently used in drilling through rocks.
- Used in paints and varnishes as a filler.
- Barium is used as paper coating pigment
- Improve physical properties of some polymer such as epoxies.
- Barium carbonate used in past as rat poison.
- Used in glass making industries.
- Barium oxide used to remove water from solvents
- Barium carbonate used in the production of chlorine and sodium hydroxide.
- Barium nitrate is used to impart green colors in fireworks.
- Barium is used as marker fluid for visualization of intestine in X-ray diagnostic test termed as barium enema.
Health Effects
The health effects of barium are due to its water-solubility and water-soluble barium compounds can be harmful to human health. The intake of barium that are water-soluble may cause paralyses and in rare cases can also lead to death.
When exposed to barium-contaminated water, a person can experience shallow breathing, increased blood pressures, irritation in stomach, weakness in muscles, changes in nerve reflexes, swelling of brains and liver, kidney [6]. In most cases, barium toxicity is an occupational hazard and the most severe health risk arise upon inhalation of vapors of barium carbonate and barium sulphate. Skin contact with barium can also lead to toxicity.
Isotopes
Barium has about 50 known isotopes ranging from 114 to 153. Most stable isotope is Barium-133 with half- life of approximately 10.51 years. Barium-130 undergo very slow reactive decay. Barium- 132 half -life thousand times greater than the age of the universe. Barium -138 lighter isotope and less abundant. Barium also has meta states out of which barium-133m1 has half –life of about 39 hours.
References
- : https://www.lenntech.com/periodic/elements/ba.htm#ixzz5T9CZ5TBr
- : http://www.chemistryexplained.com/elements/A-C/Barium.html#ixzz5T9HSG6jR
Other Periodic Table Elements
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- Hassium
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Overview
Barium was first isolated in 1808 by English chemist Sir Humphry Davy (1778-1829). In 1807 and 1808, Davy also discovered five other new elements: sodium, potassium, strontium, calcium, and magnesium. All of these elements had been recognized much earlier as new substances, but Davy was the first to prepare them in pure form. (See sidebar on Davy in the Calcium entry.)
Barium had first been identified as a new material in 1774 by Swedish chemist Carl Wilhelm Scheele (1742-86). The form with which Scheele worked, however, was a compound of barium, barium sulfate (BaSO 4 ). Barium sulfate is, in fact, the most common naturally occurring ore of barium. It is generally known as barite or barytes.
SYMBOL
Ba
ATOMIC NUMBER
56
ATOMIC MASS
137.34
FAMILY
Group 2 (IIA)
Alkaline earth metal
PRONUNCIATION
BARE-ee-um
Barium is a member of the alkaline earth metals. The alkaline earth metals make up Group 2 (IIA) of the periodic table. The other elements in this group are beryllium, magnesium, calcium, strontium, and radium. These elements tend to be relatively active chemically and form a number of important and useful compounds. They also tend to occur abundantly in the Earth's crust in a number of familiar minerals such as aragonite, calcite, chalk, Limestone, marble, travertine, magnesite, and dolomite. Alkaline earth compounds are widely used as building materials.
Barium itself tends to have relatively few commercial uses. However, its compounds have a wide variety of applications in industry and medicine. Barium sulfate is used in X-ray studies of the gastrointestinal (GI) system. The GI system includes the stomach, intestines, and associated organs.
Discovery and naming
The first mention of barium compounds goes back to the early seventeenth century. Early records mention a 'Bologna stone,' named for the the city of Bologna, Italy. The Bologna stone glowed in the dark.
For more than a hundred years, researchers labored without being able to identify the elements in the stone. In 1774, Scheele announced the presence of a new element in the Bologna stone. Today, scientists know that the stone was a form of barite. Five years later, Scheele demonstrated that barite was also present in heavy spar. This dense transparent mineral closely resembles ordinary spar, a compound of calcium.
Physical properties
Pure barium is a pale yellow, somewhat shiny, somewhat malleable metal. Malleable means capable of being hammered into thin sheets. It has a melting point of about 700°C (1,300°F) and a boiling point of about 1,500°C (2,700°F). Its density is 3.6 grams per cubic centimeter.
When heated, barium compounds give off a pale yellow-green flame. This property is used as a test for barium.
Chemical properties
Barium is an active metal. It combines easily with oxygen, the halogens, and other non-metals. The halogens are Group 17 (VIIA) of the periodic table and include fluorine, chlorine, bromine, iodine, and astatine. Barium also reacts with water and with most acids. It is so reactive that it must be stored under kerosene, petroleum, or some other oily liquid to prevent
Occurrence in nature
Barium is the fourteenth most abundant element in the Earth's crust. Its abundance is estimated to be about 0.05 percent.
The most common sources of barium are barite and witherite. Witherite is an ore containing barium carbonate (BaCO 3 ). The world's major sources of barium ores are China, India, Morocco, the United States, Turkey, and Kazakhstan. Most of the barium
Isotopes
There are seven naturally occurring isotopes of barium: barium-130, barium-132, barium-134, barium-135, barium-136, barium-137, and barium-138. Isotopes are two or more forms of an element. Isotopes differ from each other according to their mass number. The number written to the right of the element's name is the mass number. The mass number represents the number of protons plus neutrons in the nucleus of an atom of the element. The number of protons determines the element, but the number of neutrons in the atom of any one element can vary. Each variation is an isotope.
About a dozen radioactive isotopes of barium are known also. A radioactive isotope is one that breaks apart and gives off some form of radiation. Radioactive isotopes are produced when very small particles are fired at atoms. These particles stick in the atoms and make them radioactive.
None of the isotopes of barium has any practical commercial application.
Extraction
Pure barium is produced by reacting barium oxide (BaO) with aluminum or silicon:
Uses
Barium metal has relatively few uses because it is so active. This activity makes it an excellent 'getter' or 'scavenger' when removing unwanted oxygen from sealed glass containers. (Oxygen can interfere with the operation of a vacuum tube, for example.) By adding a small amount of barium to the tube, the free oxygen inside will be 'soaked up.' The oxygen reacts with the barium to form barium oxide.
Compounds
Barium Symbol
Compounds of barium, especially barite (BaSO 4 ), are critical to the petroleum industry. Barite is used as a weighting agent in drilling new oil wells. A weighting agent is a material that adds body to petroleum.
Drilling for oil used to produce huge gushers. A gusher is an oil that sprays out of the well into the air. Gushers are undesirable, because they waste oil and can burn for months if ignited.
Gushers are caused by the pressure of oil rushing into a newly drilled hole in the ground. This pressure pushes the oil upward much too rapidly. Barite is added to the hole as it is drilled. There, it tends to mix with oil in the ground and form a very dense mixture that comes out much more slowly and under control.
Ninety percent of the barite mined in the United States is used by the petroleum industry. Here are other uses of barite and other barium compounds:
Taking a look inside the body
P erhaps the best known use of barium compounds is in medicine. Doctors often want to know what is happening inside a patient's body. One way to find out, of course, is through surgery. But surgery is a drastic procedure. It can cause new problems for the patient. As a result, medical researchers have developed procedures that are less extreme. One such method is called radiography.
Radiography is a technique in which X rays are passed through the body. X rays are high energy light waves. They can pass through skin and tissue, but are absorbed by bones. So X rays are a good way of finding out if a bone is broken, for example.
Any type of light appearing on film from an X ray produces a black area, or exposure. The X rays pass through soft issues, exposing the film. Bones look greyish white on the film, depending on how much energy gets through.
Radiography can be also be used for studying parts of the body where bones are not involved. For example, a doctor might want to study a person's stomach. Since there are no bones in the stomach, some other method must be used to see inside the stomach.
Barium sulfate is often used in such cases. Barium sulfate has some of the same properties as bony material. Therefore, since X rays will not pass through barium sulfate, this compound can be used to examine certain soft tissues.
Radiography using barium sulfate is called a barium swallow or a barium enema. Barium sulfate is mixed with water into a slurry (mixture) that looks and tastes like ground-up chalk. The patient swallows the dense mixture. A doctor or nurse then holds a fluoroscope over the patient's abdomen. The fluoroscope emits X rays that show up on a television screen.
The barium sulfate-water mixture slowly travels down the patient's throat, into the stomach, through the intestines, and out through the bowels. As the barium sulfate coats the lining of the digestive tract, a doctor can see if anything is wrong.
How can a toxic compound like barium sulfate be used for this procedure? Barium sulfate does not dissolve in water. So it cannot enter the blood stream. If it cannot get into the blood, it has no toxic effects. The barium sulfate is eliminated through the bowels a few hours after the procedure.
barium sulfate (barite): used to add body to or as a coating for paper products; as a white coloring agent in paints, inks, plastics, and textiles; in the manufacture of rubber products; in the production of batteries; in medical applications (see accompanying sidebar)
barium carbonate (BaCO 3 ): used in the production of chlorine and sodium hydroxide; as rat poison; in special types of glass
barium oxide (BaO): used to remove water from solvents; in the petroleum industry
Barium Neutrons
barium nitrate (Ba(NO 3 ) 2 ): used in fireworks; as rat poison; in special ceramic glazes
Health effects
Barium Electrons
Barium and all of its compounds are very toxic.