Description
Tantalum dust is a black odorless powder. mp: 2996° C, bp: approx. 5250°C. Density: 16.65 g/cm³. Insoluble in water. Tantalum oxide dust is a white, microcrystalline powder mp: 1800°C. Density: 7.6 g/cm³. Insoluble in water. The mixture is listed as a toxic inhalation hazard by OSHA.;DryPowder; DryPowder, OtherSolid; OtherSolid; PelletsLargeCrystals;BLACK SOLID IN VARIOUS FORMS.;Steel-blue to gray solid or black, odorless powder.;Metal: Steel-blue to gray solid or black, odorless powder.
IUPAC Name
tantalum
Molecular Weight
180.9479g/mol
Molecular Formula
Ta
InChI
InChI=1S/Ta
InChI Key
GUVRBAGPIYLISA-UHFFFAOYSA-N
Boiling Point
9797 °F at 760 mm Hg (NIOSH, 2016);5429 °C;5425 °C;9797°F;9797°F
Melting Point
5425 °F (NIOSH, 2016);2996 °C;2996 °C;5425°F;5425°F
Flash Point
>250 °C
Density
16.65 (metal), 14.40 (powder) (NIOSH, 2016);14.491 g/cu cm (powder); 16.6 g/cu cm (worked metal);14.5 g/cm³;16.65 (metal) 14.40 (powder);16.65 (metal) 14.40 (powder)
Solubility
Insoluble (NIOSH, 2016);Soluble in fused alkalies; insoluble in acids except hydrofluoric and fuming sulfuric acids;Insoluble in water.;Solubility in water: none;Insoluble
Color Form
Silvery gray metal, body-centered cubic crystal structure;CUBIC OR POWDER;Gray, very hard, malleable, ductile metal;Black powder; steel-blue-colored metal when unpolished, nearly platinum white when polished;Metal: Steel-blue to gray solid or black powder.
Complexity
0
Covalently-Bonded Unit Count
1
EC Number
237-770-4;231-135-5
Exact Mass
180.948g/mol
Formal Charge
0
H-Bond Acceptor
0
H-Bond Donor
0
Heat Of Vaporization
7.53X10+5 J/mol
Heavy Atom Count
1
ICSC Number
1596
MeSH Entry Terms
Tantalum;Tantalum 181;Tantalum-181
Monoisotopic Mass
180.948g/mol
Odor
Odorless
Other Experimental
Atomic number: 73; can readily be drawn in fine wires; valences: 5, also 4, 3, 2.;Two naturally occurring isotopes: 181 (99.99877%); 180 (0.0123%) Half-life: >10+12 years; artificial isotopes: 172-179; 182-186;Specific heat (0 °C): 0.036 cal/g °C; Electrical resistivity: (18 °C): 12.4 microohm-cm;Very resistant to chemical attack; not attacked by aqueous acids other than hydrofluoric; not attacked by aqueous alkalies; slowly attacked by fused alkalies. Reacts with fluorine, chlorine, and oxygen only on heating. At high temperatures absorbs several hundred times its volume of hydrogen; combines with nitrogen, with carbon.;HAS GOOD "GETTERING" ABILITY @ HIGH TEMP;Tensile strength of drawn wire may be as high as 130,000 psi; expansion coefficient 8X10-6 over range 20-1500 °C; Electrical resistivity: 13.6 microohm-cm @ 0 °C; 32.0 microohm-cm @ 500 °C; dust or powder may be flammable.;99.5% pure tantalum is resistant to all concentrations of hot and cold sulfuric acid (except concentrated boiling); hydrochloric acid, nitric and acetic acids, hot and cold dilute sodium hydroxide, all dilutions of hot and cold ammonium hydroxide, mine and seawaters, moist sulfurous atmospheres, aqueous solutions of chlorine;Enthalpy of formation (gas) 782.0 kJ/mol; Heat capacity: 25.4 J/K mol (crystal); 20.9 J/K mol (gas);Thermal conductivity: 0.540 J/cm °C @ 20 °C; 0.680 J/cm °C @ 568 °C; 0.720 J/cm °C @ 828 °C; Enthalpy of fusion: 31,400 J/mol;Maximum valence +5; oxidation states of +4, +3, and +2 are known, but are unstable forms;The dry powder ignites spontaneously in air.
Refractive Index
Index of refraction: 2.05
Rotatable Bond Count
0
RTECS Number
WW5505000
UNII
6424HBN274
UN Number
3089;3089
Vapor Pressure
0 mm Hg (approx) (NIOSH, 2016);1 kPa @ 3024 °C; 10 Pa @ 3324 °C; 100 Pa @ 3684 °C; 1 kPa @ 4122 °C; 10 k Pa @ 4666 °C; 100 kPa @ 5361 °C;0 mmHg (approx);0 mmHg (approx)
