56	Ba	Barium
Atomic Weight: 137.327				Shells: 2,8,18,18,8,2
Group: Alkali Earth				Filling orbital: 6s2
Crystal Structure: Cubic body centered				Covalent radius: 1.98 Å
Oxidation States: +2				Atomic radius: 2.78 Å
Electronegativity, Pauling: 0.89				Atomic volume: 39.24 cm³/mol
State at RT: Solid				First ionization potential: 5.212 V
Melting Point: 1002°K				2nd ionization potential: 10.004 V
Boiling Point: 1910°K				3rd ionization potential: ?
Density @ 293°K: 3.51 g/cm³				Specific heat: 0.204 J/gK
Electrical conductivity: 0.030 106/cm ohm				Heat of vaporization: 142.0 kJ/mol
Thermal conductivity: 0.184 W/cmK				Heat of fusion: 7.750 kJ/mol
Element Nuclides
Nuclide		Abundance	Weight	Spin	Half-Life	Decay Modes
Ba130		0.101%	129.9063	0		Stable
Ba131		0.%	131.	.5	11.7d	EC, +
Ba132		9.7e-002%	131.905	0		Stable
Ba133		0.%	133.	.5	10.53y
Ba133m		0.%	133.	5.5	1.621d	IT,
Ba134		2.42%	133.9045	0		Stable
Ba135		6.59%	134.9057	1.5		Stable
Ba135m		0.%	135.	5.5	1.20d	IT
Ba136		7.81%	135.9046	0		Stable
Ba137		11.32%	137.9058	1.5		Stable
Ba137m		0.%	137.	5.5	2.552m	IT
Ba138		71.66%	137.9052	0		Stable
Ba139		0.%	139.	3.5	1.396h	-
Ba140		0.%	140.	0	12.75d	-
Ba141		0.%	141.	1.5	18.3m	-
Ba142		0.%	142.	0	10.7m	-

Name origin: Greek: barys (heavy or dense).
Description: Soft heavy silver colored metal.
Discovered by: Sir Humphrey Davy
Year: 1808
Location: England
Sources: Found in barytine (BaSO₄) and witherite (BaCO₃), never found in pure form due to its reactivity. Must be stored under kerosene to remain pure.
Uses: ?

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Registry Numbers

• CAS: 7440-39-3
• RTECS: CQ8370000
• DOT (UN): 1400
• NFPA ratings (1-4)
  • Health: 2
  • Flammability: 2

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Description
yellowish-white, slightly lustrous lumps. flammable solid

Incompatabilities
moisture

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From DOT guidebook, Guide Number 40

Fire or Explosion Hazards
May ignite itself if exposed to air.
May re-ignite after fire is extinguished.
May ignite in presence of moisture.
Contact with water produces flammable gas.
Runoff to sewer may create fire or explosion hazard.

Health Hazards
If inhaled, may be harmful.
Contact may cause burns to skin and eyes.
Fire may produce irritating or poisonous gases.

Emergency Action: General
Keep unnecessary people away. Stay upwind; keep out of low areas.
Isolate hazard area and deny entry.
Wear self-contained breathing apparatus and full protective clothing.
Also, in case of water pollution call local authorities.
FOR EMERGENCY ASSISTANCE CALL CHEMTREC (800) 424-9300

Emergency Action: Fire
DO NOT USE WATER OR FOAM.
SMALL FIRES: Dry chemical, soda ash or lime.
LARGE FIRES: Withdraw form area and let fire burn.
MAGNESIUM FIRES: Use dry sand, Met-L-X powder or G-1 graphite powder.
Do no use water.
Move container from fire area if you can do it without risk.

Emergency Action: Spill or Leak
Do not touch spilled material. No flares, smoking or flames in hazard area.
Do not get water inside containers. No water on spilled material.
SMALL DRY SPILLS: Shovel into dry containers and cover; move containers
then flush area with water.

Emergency Action: First Aid
Move victim to fresh air; call emergency medical care.
Remove and isolate contaminated clothing and shoes.
Wipe material from skin immediately; then flush skin or eyes with running
water for at least 15 minutes.

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Material Saftey Data Sheet (MSDS)
Still more information

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Return to the Periodic Table