| Identification | More | [Name]
Barium | [CAS]
7440-39-3 | [Synonyms]
bario
BARIUM
barium(0)
BARIUM, ROD
BARIUM METAL
Barium, 99+%
Barium powder
Barium element
BARIUM STANDARD
bario (spanish)
baryum (french)
BariuM solution
High pure Barium
BA Target 99.95%
BARIUM AA STANDARD
BARIUM ICP STANDARD
BARIUM PIECES 99%
Ba Standard Solution
BARIUM PIECES (99.7%)
Barium Rod, 22mm Dia.
BariuM ingot,30-50MM.
BARIUM ROD , (SR<1.6%)
BARIUM PIECES DENDRITIC
BARIUM STANDARD SOLUTION
Barium Metal (dendritic)
Bariumrod(99+%,Sr-<1.6%)
BARIUM ROD ( 99+% SR-0.8%)
BARIUM IN LIQUID PARAFFIN,
Barium ISO 9001：2015 REACH
Barium Rod, 22mm Dia. 99.5%
BARIUM A.A STANDARD SOLUTION
BARIUM PIECES (DENDRITIC), 3N
BARIUM, AAS STANDARD SOLUTION
BARIUM AA STANDARD CONCENTRATE
BARIUM SINGLE ELEMENT STANDARD
BARIUM PLASMA EMISSION STANDARD
Barium rod, 22mm (0.9 in.) dia.
Barium, rod 22mm diameter 99.5%
BARIUM STANDARD SOLUTION 100 ML
BARIUM STANDARD SOLUTION 500 ML
BARIUM PIECES DENDRITIC (99.9%)
BARIUM, DENDRITIC PIECES, 99.9%
Barium pieces (99.7%, Sr-<1.0%)
BARIUM, GRANULES, UNDER OIL, 99%
BARIUM, PLASMA STANDARD SOLUTION
BARIUM SINGLE COMPONENT STANDARD
Barium compounds, soluble (as Ba)
BARIUM AA SINGLE ELEMENT STANDARD
BARIUM ATOMIC ABSORPTION STANDARD
Barium, rods, ca. 2 cm diam., 99+%
BARIUM STICKS UNDER PARAFFIN OIL
BARIUM RODS DIAMETER ABOUT 2 CM 99+
BARIUM, OIL BASED STANDARD SOLUTION
BARIUM ATOMIC SPECTROSCOPY STANDARD
BARIUM SINGLE ELEMENT PLASMA STANDARD
Barium Single Element Aqueous Solution
Barium, dendritic pieces in mineral oil
BARIUM AA/ICP CALIBRATION/CHECK STANDARD
BARIUM ICP STANDARD TRACEABLE TO SRM FRO
BARIUM DISTILLED DENDRITIC PIECES &
Barium atomic absorption standard solution
Standard solution for barium determination
Barium, AAS standard solution, Ba 1000μg/mL
Barium, rods, ~2cm diam., 99+% metals basis
Barium, rods, ca. 2 cm diam. in mineral oil
Barium, plasma standard solution, Specpure?
Barium pieces, 1 cm, 99% trace metals basis
BARIUM PLASMA EMISSION SPECTROSCOPY STANDARD
BARIUM, DISTILLED, DENDRITIC PIECES, 99. 99%
Barium, plasma standard solution, Ba 10μg/mL
Barium,99.9%,dendritic pieces in mineral oil
Barium plasma standard solution, Ba 10000μg/mL
Barium, dendritic pieces in mineral oil, 99.9%
Barium, dendritic pieces in mineral oil, 99.90%
BARIUM, 99.90%, DENDRITIC PIECES IN MINERAL OIL
Barium,99+%,rods, ca. 2 cm diam. in mineral oil
Barium Oil based standard solution, Ba 1000μg/g
Barium, Oil based standard solution, Ba 5000μg/g
BARIUM ATOMIC ABSORPTION SINGLE ELEMENT STANDARD
Barium, Reference Standard Solution, 1000ppm ± 1%
BariuM rod, diaM. ~2 cM, >=99% trace Metals basis
Barium, rods, ca. 2 cm diam. in mineral oil, 99+%
Bariumrod,22mm(0.9in)dia,99+%(metalsbasis),Sr=0.8%
Barium rod, 22mm (0.9 in.) dia. x 450mm (17.7 in.)
Barium, plasma standard solution, Specpure, Ba 10g/ml
Bariumpieces,2.5cm(1in)&down,99.2%(metalsbasis),Sr=0.8%
Barium rod, 22mm dia., 99% trace metals basis, Sr ≤0.8%
Barium, AAS standard solution, Specpure(R), Ba 1000μg/ml
BariuM pieces, 1-3MM (0.04-0.12in). 99.9% (Metals basis)
BariuM, 99+%, rods, approx. 2 cM diaMeter, in Mineral oil
Barium, plasma standard solution, Specpure(R), Ba 1000μg/ml
Barium, Oil based standard solution, Specpure(R), Ba 5000μg/g
Barium, Oil based standard solution, Specpure(R), Ba 1000μg/g
Barium, plasma standard solution, Specpure(R), Ba 10,000μg/ml
BariuM beads, 0.5-2.0 MM particle size, 99% trace Metals basis
BariuM, 99.9%, (trace Metal basis), dendritic pieces, under Argon
Barium dendritic pieces, purified by distillation, 99.9% trace metals basis
Barium dendritic pieces, purified by distillation, 99.99% trace metals basis
Barium rod, 22mm (0.9in) dia x 450mm (17.7in), 99+% (metals basis), Sr ≤0.8%
Barium solid, crystalline dendritic, ampuled under argon, 99.9% trace metals basis | [EINECS(EC#)]
231-149-1 | [Molecular Formula]
Ba | [MDL Number]
MFCD00134031 | [Molecular Weight]
137.33 | [MOL File]
7440-39-3.mol |
| Chemical Properties | Back Directory | [Description]
Barium is a silvery-white metal. It exists in nature only in ores containing mixtures of elements.
The important combinations are the peroxide, chloride, sulphate, carbonate, nitrate,
and chlorate. The pure metal oxidises readily and reacts with water emitting hydrogen. It
combines with other chemicals such as sulphur or carbon and oxygen to form barium compounds.
Barium compounds are used by the oil and gas industries to make drilling muds.
Barium attacks most metals with the formation of alloys; iron is the most resistant to alloy
formation. Barium forms alloys and intermetallic compounds with lead, potassium, platinum,
magnesium, silicon, zinc, aluminium, and mercury. Barium compounds exhibit close
relationships with the compounds of calcium and strontium, which are also alkaline earth
metals. Twenty-five barium isotopes have been identified, 138Ba being the most abundant,
and the others are unstable isotopes with half-lives ranging from 12.8 days for 140Ba to 12 s
for 143Ba. Two of these isotopes, 131Ba and 139Ba, are used in research as radioactive tracers.
The general population is exposed to barium through air, drinking water, and food. | [Definition]
Alkaline-earth element of
atomic number 56, group IIA of periodic table; aw
137.34; valence 2; 7 stable isotopes.
| [Appearance]
Barium is a flammable, silver white or
yellowish metal in various forms including powder. Barium
may ignite spontaneously in air in the presence of moisture,
evolving hydrogen. | [Melting point ]
725 °C(lit.)
| [Boiling point ]
1640 °C(lit.)
| [density ]
3.6 g/mL at 25 °C(lit.)
| [storage temp. ]
water-free area | [solubility ]
reacts with H2O; slightly soluble in ethanol | [form ]
rod
| [color ]
Silver-gray | [Specific Gravity]
3.51 | [Stability:]
Stability Reacts vigorously or violently with acids, water, tetrachloromethane, small halogenated hydrocarbons. Should be stored under an inert material such as petroleum ether to exclude air. Flammable. | [Resistivity]
50.0 μΩ-cm, 20°C | [Water Solubility ]
soluble with H2 evolution in cold H2O and hot H2O; slightly soluble alcohol; insoluble benzene [CRC10] | [Sensitive ]
air sensitive, moisture sensitive | [Merck ]
13,967 | [Exposure limits]
TLV-TWA 0.5 mg/m3 (for soluble compounds)
(ACGIH and MSHA); IDLH (for
soluble compounds) 250 mg/m3 (NIOSH).
. | [History]
Baryta was
distinguished from lime by Scheele in 1774; Barium was
discovered by Sir Humphrey Davy in 1808. It is found only in
combination with other elements, chiefly in barite or heavy
spar (sulfate) and witherite (carbonate) and is prepared by
electrolysis of the chloride. Large deposits of barite are found
in China, Germany, India, Morocco, and in the U.S. Barium
is a metallic element, soft, and when pure is silvery white like
lead; it belongs to the alkaline earth group, resembling calcium
chemically. The metal oxidizes very easily and should be
kept under petroleum or other suitable oxygen-free liquids to
exclude air. It is decomposed by water or alcohol. The metal is
used as a “getter” in vacuum tubes. The most important compounds
are the peroxide (BaO2), chloride, sulfate, carbonate,
nitrate, and chlorate. Lithopone, a pigment containing barium
sulfate and zinc sulfide, has good covering power, and does
not darken in the presence of sulfides. The sulfate, as permanent
white or blanc fixe, is also used in paint, in X-ray diagnostic
work, and in glassmaking. Barite is extensively used as
a weighting agent in oilwell drilling fluids, and also in making
rubber. The carbonate has been used as a rat poison, while
the nitrate and chlorate give green colors in pyrotechny. The
impure sulfide phosphoresces after exposure to the light. The
compounds and the metal are not expensive. Barium metal
(99.2 + % pure) costs about $3/g. All barium compounds that
are water or acid soluble are poisonous. Naturally occurring
barium is a mixture of seven stable isotopes. Thirty-six other
radioactive isotopes and isomers are known to exist. | [CAS DataBase Reference]
7440-39-3(CAS DataBase Reference) | [EPA Substance Registry System]
Barium (7440-39-3) |
| Hazard Information | Back Directory | [Chemical Properties]
Barium is a silvery-white metal. It exists in nature only in ores containing mixtures of ele-
ments. The important combinations are peroxide, chloride, sulfate, carbonate, nitrate, and
chlorate. The pure metal oxidizes readily and reacts with water, emitting hydrogen. It com-
bines with other chemicals such as sulfur or carbon and oxygen to form barium compounds.
Barium compounds are used by the oil and gas industries to make drilling muds. Barium
attacks most metals with the formation of alloys; iron is the most resistant to alloy formation.
Barium forms alloys and intermetallic compounds with lead, potassium, platinum, mag-
nesium, silicon, zinc, aluminum, and mercury. Barium compounds exhibit close relation-
ships with the compounds of calcium and strontium, which are also alkaline earth metals.
Doctors sometimes use barium sulfate to perform medical tests and to take x-rays of the
gastrointestinal tract. Twenty-i ve barium isotopes have been identii ed.
138Ba is the most
abundant; the others are unstable isotopes with half-lives ranging from 12.8 days for
140Ba
to 12 sec for
143Ba. Two of these isotopes,
131Ba and
139Ba, are used in research as radioactive
tracers. The general population is exposed to barium through air, drinking water, and food. | [General Description]
Barium alloy, pyrophoric is mixture of barium and other metals or nonmetallic elements to improve the specific usefulness of barium. Barium alloys are a solid and can ignite spontaneously in contact with air. This material is toxic and products given off in fire could be very toxic. | [Reactivity Profile]
Alloys containing a substantial amount of barium react violently with acids [Lab. Gov. Chemist 1965]. | [Air & Water Reactions]
Finely divided metal powder is pyrophoric, ignites spontaneously in air [Bretherick 1979 p. 170-171]. Alloys containing a substantial proportion of barium rapidly decomposed water. The heat of the reaction is sufficient that the evolved hydrogen may ignite [Lab. Govt. Chemist 1965]. | [Hazard]
Flammable (pyrophoric) at room tem-
perature in powder form; store under inert gas,
petroleum, or other oxygen-free liquid. When
heated to approximately 200C in hydrogen, barium
reacts violently, forming BaH2. Eye, skin, and gas-
trointestinal irritant, and muscular stimulant. Ques-
tionable carcinogen.
| [Health Hazard]
Fire will produce irritating, corrosive and/or toxic gases. Inhalation of decomposition products may cause severe injury or death. Contact with substance may cause severe burns to skin and eyes. Runoff from fire control may cause pollution. | [Health Hazard]
The health effects of barium compounds depend on how well the compound dissolves
in water or in the stomach contents. Barium compounds that do not dissolve well, such
as barium sulfate, are considered not harmful. Barium carbonate dust and barium oxide
dust have been reported to be a bronchial irritant. While barium carbonate is a dermal
irritant, barium oxide is a nasal irritant. Occupational workers exposed to barium dust,
usually in the form of barium sulfate or carbonate, often develop a benign pneumoco-
niosis also called “baritosis.” The effect of baritosis has been shown to be reversible and
has not caused any kind of severe pulmonary adverse effect. Barium compounds that
do not dissolve in water are considered safe. However, the health effects of the different
barium compounds depend on the degree of their water solubility. The compounds that
dissolve well in water are known to cause harmful health effects when ingested in high
levels. Symptoms of poisoning include stomach irritation, brain swelling, muscle weak-
ness, liver and kidney damage, adverse effects to the heart, increased blood pressure,
changes in heart rhythm, effects on the spleen, difi culties in breathing, and swelling of
the brain. Exposures to high concentrations of barium through food and drinking water cause gastrointestinal disturbances. Barium causes vomiting, abdominal cramps, diar-
rhea, difi culties in breathing, increased or decreased blood pressure, numbness around
the face, and muscle weakness, changes in heart rhythm or paralysis, and possibly death.
Animals exposed to barium over long periods showed kidney damage, decreased body
weight, and fatal injury. Ingestion of large amounts of barium chloride (2 and 4 g) causes
fatal injury, because barium ions paralyze the heart. Acute poisoning with barium causes
nausea and diarrhea, cardiac problems, and muscular spasms, as well as cardiac arrest.
Thus, barium, at concentrations normally found in our environment, does not pose any
signii cant risk for the general population. However, for specii c subpopulations and
under conditions of high barium exposure, the potential for adverse health effects should
be taken into account. | [Potential Exposure]
Metallic barium is used for removal of
residual gas in vacuum tubes and in alloys with nickel, lead,
calcium, magnesium, sodium, and lithium. Barium compounds
are used in the manufacture of lithopone (a white
pigment in paints), chlorine, sodium hydroxide, valves, and
green flares; in synthetic rubber vulcanization; X-ray diagnostic
work, glassmaking, papermaking, beet-sugar purification;
animal and vegetable oil refining. They are used in the
brick and tile, pyrotechnics, and electronics industries. They
are found in lubricants, pesticides, glazes, textile dyes and
finishes; pharmaceuticals; in cements which will be exposed
to saltwater; and barium is used as a rodenticide, a flux for
magnesium alloys, a stabilizer and mold lubricant in the rubber
and plastics industries, an extender in paints; a loader for
paper, soap, rubber, and linoleum; and as a fire extinguisher
for uranium or plutonium fires. | [Fire Hazard]
Flammable/combustible material. May ignite on contact with moist air or moisture. May burn rapidly with flare-burning effect. Some react vigorously or explosively on contact with water. Some may decompose explosively when heated or involved in a fire. May re-ignite after fire is extinguished. Runoff may create fire or explosion hazard. Containers may explode when heated. | [First aid]
Move victim to fresh air. Call 911 or emergency
medical service. Give artificial respiration if victim is not
breathing. Do not use mouth-to-mouth method if victim
ingested or inhaled the substance; give artificial respiration
With the aid of a pocket mask equipped with a one-way
valve or other proper respiratory Medical device.
Administer oxygen if breathing is difficult. Remove and isolate
contaminated clothing and shoes. In case of contact with
substance, immediately flush skin or eyes with running
water for at least 20 minutes. For minor skin contact, avoid
spreading material on unaffected skin. Keep victim warm
and quiet. Effects of exposure (inhalation, ingestion or skin
contact) to substance may be delayed. Ensure that medical
personnel are aware of the material(s) involved and take precautions
to protect themselves. Medical observation is
recommended for 24 to 48 hours after breathing overexposure,
as pulmonary edema may be delayed. As first aid for
pulmonary edema, a doctor or authorized paramedic may
consider administering a drug or other inhalation therapy.
| [Shipping]
UN1400 Barium, Hazard Class: 4.3; Labels:
4.3—Dangerous when wet material. UN1854 Barium alloys,
pyrophoric, Hazard Class: 4.2; Labels: 4.2—Spontaneously
combustible material. UN1564 Barium compound, n.o.s.,
Hazard Class: 6.1; Labels: 6.1—Poisonous materials. | [Incompatibilities]
Barium powder may spontaneously
ignite on contact with air. It is a strong reducing agent and
Barium 337
reacts violently with oxidizers and acids. Reacts with water,
forming combustible hydrogen gas and barium hydroxide.
Reacts violently with halogenated hydrocarbon solvents,
causing a fire and explosion hazard. | [Waste Disposal]
Barium in solution (see spill
handling) may be precipitated with soda ash and the sludge
may be landfilled. | [Physical properties]
Barium is the fifth element in group 2 (IIA) of the alkali earth metals and has most of theproperties and characteristics of the other alkali earth metals in this group. For example, theyall are called alkaline earths because, when first discovered, they exhibited both characteristicsof alkaline (basic) substances and characteristics of the earth from which they came. Ancienthumans did not know they were metals because their metallic forms do not exist in nature.Barium is a silvery metal that is somewhat malleable and machineable (can be worked on alathe, stretched and pounded). Its melting point is 725°C, its boiling point is about 1640°C,and its density is 3.51 g/cm3. (The accurate figures for its properties are difficult to determinebecause of barium’s extreme activity—the pure metal will ignite when exposed to air, water,ammonia, oxygen, and the halogens. | [Isotopes]
Naturally occurring barium is a mixture of seven stable isotopes: barium-138 (71.66%), barium-137 (11.32%), barium-136 (7.81%), barium-135 (6.59%), barium-134 (2.42%), barium-130 (0.101%), and barium- 132 (0.097%). About six times this many radioactive isotopes have been prepared with mass numbers ranging from 114 to 153. Of the 40 isotopes known, most are highly radioactive and have half-lives in the several milliseconds to a few days range. The only notable exceptions are 133Ba with a half-life of 10.51 years, 128Ba (2.43 days), 141Ba (11.50 days) and 140Ba (12.75 days). | [Origin of Name]
The name barium is derived from the Latin word barys, which means
“heavy. | [Characteristics]
When barium burns in air, it produces barium oxide (2Ba + O2 → 2BaO). When metallicbarium burns in water, it forms barium hydroxide [Ba + 2H2O → Ba(OH)2 + H2↑]. Severalbarium compounds burn with a bright green flame, which make them useful for fireworks.Barium is more reactive with water than are calcium and strontium. This is a result of thevalence electrons’ being further from the positive nucleus. Therefore, barium is more electronegative than the alkali earth metals with smaller nuclei.In powdered form, it will burst into a bright green flame at room temperature. | [Production Methods]
The minerals are BaSO4 and BaCO3. Metal barium is obtained by reducing the barium oxide at a high temperature in vacuum with Al or Si or by doing electrolysis with the Hg cathode and evaporating Hg of amalgam formed at the process slowly to segregate Ba. To obtain vacuum evaporated films, direct heating with the conical basket of W, Ta, Mo, Nb, Ni, Fe, chromel, etc., or with the boat of Ta, Mo is used. Ba reacts with alumina. The rate of evaporation is 2.28×10-4 g/cm2 s with the evaporation temperature of 629 ℃. | [Purification Methods]
Barium is cleaned by washing with diethyl ether to remove adhering paraffin, then filed in an argon-filled glove box, washed first with ethanol containing 2% conc HCl, then with dry ethanol. It is dried in a vacuum and stored under argon [Addison et al. J Chem Soc 3868 1962]. It has also been purified by double distillation under 10mm of argon pressure. | [Industrial uses]
Barium (symbol Ba) is a metallic element thatoccurs in combination in the minerals witheriteand barite, which are widely distributed. Themetal is silvery white in color and can beobtained by electrolysis from the chloride, butit oxidizes so easily that it is difficult to obtainin the metallic state. Its melting point is 850°C,and its specific gravity 3.78. The most extensiveuse of barium is in the form of its compounds.The salts that are soluble, such as sulfide andchloride, are toxic. An insoluble, nontoxic bariumsulfate salt is used in radiography. Bariumcompounds are used as pigments, in chemicalmanufacturing, and in deoxidizing alloys of tin, copper, lead, and zinc. Barium is introducedinto lead-bearing metals by electrolysis toharden the lead.Barium is also a key ingredient in ceramicsuperconductors. | [Environmental Fate]
Ingestion of toxic doses of barium affects the muscles, especially
the heart. Barium has a digitalis-type effect on the heart.
Ventricular fibrillation and slowed pulse rate are noted. This
may be related to barium’s tendency to displace potassium; the
resulting potassium deficiency causes muscle weakness. | [storage]
Color Code—Yellow Stripe (strong reducingagent): Reactivity Hazard; Store separately in an area isolated from flammables, combustibles, or other yellow codedmaterials. Barium metal should be stored in a dry area, separated from halogenated solvents, strong oxidants, acids, intightly-closed containers under an inert gas blanket, petroleum, or oxygen-free liquid. Rubber gloves, rubber protective clothing and apron, goggles and gas-filter mask shouldbe worn when working in a barium storage area. | [Structure and conformation]
The space lattice of Barium belongs to the cubic system, and its body-centered cubic lattice has a lattice constant of a=0.5009 nm. | [Toxicity evaluation]
Barium is a highly reactive metal that occurs naturally only in
a combined state. The element is released to environmental
media by both natural processes and anthropogenic sources.
Barium is released primarily to the atmosphere as a result of
industrial emissions during the mining, refining, and production
of barium and barium chemicals, fossil fuel combustion,
and entrainment of soil and rock dust into the air. In addition,
coal ash, containing widely variable amounts of barium, is also
a source of airborne barium particulates. Most barium released
to the environment from industrial sources is in forms that do
not become widely dispersed. In the atmosphere, barium is
likely to be present in particulate form. Although chemical
reactions may cause changes in speciation of barium in air, the
main mechanisms for the removal of barium compounds from
the atmosphere are likely to be wet and dry depositions. | [Toxics Screening Level]
The ITSL for barium is 5 μg/m3 based on an 8-hour averaging time. |
| Safety Data | Back Directory | [Hazard Codes ]
C,Xi,F | [Risk Statements ]
R25:Toxic if swallowed.
R26:Very Toxic by inhalation.
R34:Causes burns.
R36/37/38:Irritating to eyes, respiratory system and skin .
R14/15:Reacts violently with water, liberating extremely flammable gases .
R11:Highly Flammable. | [Safety Statements ]
S23:Do not breathe gas/fumes/vapor/spray (appropriate wording to be specified by the manufacturer) .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S36:Wear suitable protective clothing .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S43:In case of fire, use ... (indicate in the space the precise type of fire-fighting equipment. If water increases the risk add-Never use water) .
S36/37:Wear suitable protective clothing and gloves .
S16:Keep away from sources of ignition-No smoking . | [OEB]
C | [OEL]
TWA: 0.5 mg/m3 | [RIDADR ]
UN 3264 8/PG 3
| [WGK Germany ]
3
| [RTECS ]
CQ8370000
| [TSCA ]
Yes | [HazardClass ]
8 | [PackingGroup ]
III | [HS Code ]
28051910 | [Safety Profile]
Water and stomach
acids solubilize barium salts and can cause
poisoning. Symptoms are vomiting, colic,
diarrhea, slow irregular pulse, transient
hypertension, and convulsive tremors and
muscular paralysis. Death may occur in a
few hours to a few days. Half-life of barium
in bone has been estimated at 50 days. Dust
is dangerous and explosive when exposed to
heat, flame, or chemical reaction. Violent or
explosive reaction with water, CCh,
fluorotrichloromethane, trichloroethylene,
and C2Cl4. Incompatible with acids, C2CLF3,
C2H2FCl3, C2HCl3 and water, 1,1,2-
trichlorotrifluoroethane, and
fluorotrichloroethane. The powder may
ignite or explode in air or other oxidizing
gases. See also BARIUM COMPOUNDS. | [Hazardous Substances Data]
7440-39-3(Hazardous Substances Data) | [Toxicity]
An element; the heaviest
of the stable alkaline earths. Barium sulfate is used as a
diagnostic aid in radiology due to its radio-opaqueness and,
because of its insolubility and lack of absorption, it is safe barring
iatrogenic episodes. Poisoning usually results from deliberate
or accidental ingestion of soluble barium compounds.
The Ba2+ ion is a muscle poison due to the blocking of the K1
channels of the Na+/K+ pump in cell membranes. Because
cases of barium poisoning are accompanied by severe hypokalemia,
potassium infusion is an effective antidote. The toxicity
of barium compounds depends on their solubility, with the free
ion being readily absorbed from gastrointestinal tract or lung,
whereas the sulfate is essentially unabsorbed. Thus, administration
of soluble sulfates immediately after ingestion is
another effective antidote. | [IDLA]
50 mg Ba/m3 |
| Questions And Answer | Back Directory | [Chemical Properties]
Barium has the symbol Ba, atomic number 56, and is the fifth element in Group 2. Its atomic weight is 137.332 g/mol. Barium is a soft silvery metal. It is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as “Baryta” but because it reacts with water and carbon dioxide, it is not found as a mineral. The most common naturally occurring minerals are the very insoluble barium sulfate, BaSO4 (Barite), and barium carbonate, BaCO3 (Witherite). Barium s name originates from the Greek word bary , meaning heavy , describing the high density of some common barium-containing ores. Alchemists in the early Middle Ages knew about some barium minerals. Smooth pebble-like stones of mineral Baryte found in Bolona, Italy were known as Bologna Stones . After exposed to light, they would glow for years (probably because they contained some barium sulfide (BaS) formed during the calcination of the stone with charcoal carbon). It was this quality that attracted them to witches and alchemists.
Though barium minerals are dense, barium metal itself is comparatively light. Its cosmic abundance is estimated as 3.7 atoms (on the same basis, Si=106 atoms). Barium constitutes about 0.03% of the Earth s crust, chiefly as the minerals Barite (also called barytes or heavy spar) and Witherite . The abundance of barium is 0.0425% in the Earth s crust and 13 mg/l in seawater. A rare gem containing barium is known, called Benitoite (BaTiSi3O9). Large deposits of Barite are found in China, Germany, India, Morocco, and in the US. Because barium quickly oxidizes in air, it is difficult to obtain the free metal and it is never found free in nature. Barium is a soft and ductile metal. Its simple compounds are notable for their relatively high specific gravity (as compared to the other alkaline earth elements). Barium, which is slightly harder than lead, has a silvery white luster when freshly cut. | [Defination]
Symbol Ba; atomic number 56; atomic weight 137.327; a Group IIA (Group 2) alkaline earth element; electronic configuration [Xe]s2; valence state +2; ionic radius of Ba2+ in crystal (corresponding to coordination number 8) 1.42 Å; first ionization potential 10.00eV; stable isotopes and their percent abundances: Ba–138 (71.70), Ba–137 (11.23), Ba–136 (7.85), Ba–135 (6.59), Ba–134 (2.42); minor isotopes: Ba–130 (0.106) and Ba–132 (0.101); also twenty-two radioisotopes are known.
| [Occurrence]
Barium was discovered in 1808 by Sir Humphrey Davy. Its abundance in the earth’s crust is about 0.0425% (425 mg/kg). The element also is found in sea water at trace concentration, 13 μg/L. It occurs in the minerals barite or heavy spar (as sulfate) and witherite (as carbonate).
| [Uses]
The most important use of barium is as a scavenger in electronic tubes. The metal, often in powder form or as an alloy with aluminum, is employed to remove the last traces of gases from vacuum and television picture tubes. Alloys of barium have numerous applications. It is incorporated to lead alloy grids of acid batteries for better performance; and added to molten steel and metals in deoxidizing alloys to lower the oxygen content. Thin films of barium are used as lubricant suitable at high temperatures on the rotors of anodes in vacuum X-ray tubes and on alloys used for spark plugs. A few radioactive isotopes of this element find applications in nuclear reactions and spectrometry.
|
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Alfa Aesar
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400-6106006 |
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http://chemicals.thermofisher.cn |
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