Argon

	18	Ar	Argon
Atomic Weight: 39.948				Shells: 2,8,8
Group: Noble Gas				Filling orbital: 3p⁶
Crystal Structure: Cubic face centered				Covalent radius: 0.98 Å
Oxidation States: 0				Atomic radius: 0.88 Å
Electronegativity, Pauling: 1.93				Atomic volume: 28.5 cm³/mol
State at RT: Gas				First ionization potential: 15.759 V
Melting Point: 83.8°K				2nd ionization potential: 27.629 V
Boiling Point: 87.3°K				3rd ionization potential: 40.74 V
Density @ 293°K: 0.0017824 g/cm³				Specific heat: 0.520 J/gK
Electrical conductivity: 0.630 10⁶/cm ohm				Heat of vaporization: 6.447 kJ/mol
Thermal conductivity: 0.0001772 W/cmK				Heat of fusion: 1.188 kJ/mol

Element Nuclides
Nuclide		Abundance	Weight	Spin	Half-Life	Decay Modes
Ar36		0.337%	34.9675	0		Stable
Ar37		0.%	36.966	1.5	35.0d
Ar38		6.3e-002%	37.9627	0		Stable
Ar39		0.%	38.964	3.5	269y	^-
Ar40		99.6%	39.9624	0		Stable
Ar41		0.%	41.	3.5	1.82h	^-

Name origin: Greek: argon (inactive).
Description: Colorless, odorless, tasteless noble gas.
Discovered by: Sir William Ramsey, Baron Rayleigh
Year: 1894
Location: Scotland
Sources: Forms almost 1% of atmosphere. Continuously released into the air by decay of radioactive potassium-40.
Uses: Lighting and other uses for non-reactive gases.

Registry Numbers

CAS: 7440-37-1
RTECS: CF2300000
DOT (UN): 1006

From DOT guide book, Guide Number 12

Fire or Explosion Hazards
Some of these materials may burn but do not ignite readily. Container may
explode in heat or fire.

Health Hazards
Vapors may cause dizziness or suffocation. Contact with liquid may cause
frostbite. 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.

FOR EMERGENCY ASSISTANCE CALL CHEMTREC (800) 424-9300

Emergency Action: Fire
Small Fires: Dry chemical or CO2.
Large Fires: Water spray, fog or foam.
Move container from fire area if you can do it without risk. Stay away from
ends of tanks. Cool containers that are exposed to flames with water from the
side until well after fire is out.

Emergency Action: Spill or Leak
Stop leak if you can do it without risk.

Emergency Action: First Aid
Move victim to fresh air; call emergency medical care. If not breathing, give
artificial respiration. If breathing is difficult, give oxygen.

Material Saftey Data Sheet

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