General | States | Energies | Oxidation & Electrons |Appearance & Characteristics
Reactions | Other Forms |Radius | Conductivity | Abundance
Encyclopedia Britannica articles


Name Tantalum Symbol Ta
atomic number 73 Atomic weight 180.947
Density @ 293 K 16.6 g/cm3 Atomic volume 10.90 cm3/mol
Group Trans. Met. discovered 1802


state (s, l, g) s
melting point 3269.2 K boiling point 5807 K
Heat of fusion 31.60 kJ/mol Heat of vaporization 743.0 kJ/mol
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1st ionization energy 761 kJ/mole electronegativity 1.5
2nd ionization energy kJ/mole electron affinity 31.1 kJ/mole
3rd ionization energy kJ/mole Specific heat 0.14 J/gK
heat atomization 782 kJ/mole atoms

Oxidation & Electrons

Shells 2,8,18,32,11,2 electron configuration [Xe] 4f14 5d3 6s2
minimum oxidation number -1 maximum oxidation number 5
min. common oxidation no. 0 max. common oxidation no. 5
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Appearance & Characteristics

structure bcc: body-centered cubic color gray
uses surg. implants,heat exch. toxicity
hardness mohs characteristics hard, inert at <100 /td deg.c>


reaction with air none reaction with 6M HCl none
reaction with 6M HCl none reaction with 15M HNO3 none
reaction with 6M NaOH none
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Other Forms

number of isotopes 2 hydride(s) TaH
oxide(s) TaO2 Ta2O5 chloride(s) TaCl3 TaCl4 TaCl5


ionic radius (2- ion) pm ionic radius (1- ion) pm
atomic radius 146 pm ionic radius (1+ ion) pm
ionic radius (2+ ion) pm ionic radius (3+ ion) 86 pm
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thermal conductivity 57.5 J/m-sec-deg electrical conductivity 80.321 1/mohm-cm
polarizability 13.1 A^3


source Tantalite (oxide) rel. abund. solar system -1.684 log
abundance earth's crust 0.3 log cost, pure 120 $/100g
cost, bulk $/100g
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World Wide Web presentation of Chemicool Periodic Table is © Copyright 1996-99 by David D. Hsu. Some data were provided by and used with the permission of JCE Software and is owned and copyright by the Division of Chemical Education, Inc. Additional data were provided by Perkin-Elmer through Peter Lykos of IIT. The information may not be redistributed without the permission of David Hsu or JCE Software.