Mendeleev's Periodic Table > Ta - Tantalum

Ta - Tantalum

Tantalum, the third member of the acid earth family, is a hard metal with reactivity lower even than platinium. The 'element' columbium was discovered in columbite minerals from Connecticut by Charles Hatchett in 1801. Columbium however was shown to be two metals one of which was tantalum. (The other was niobium.) Tantalum oxide was isolated by Anders G. Ekeberg in 1802 who then named the element because it tantalized his efforts to purify the metal. The pure metal was finally obtained, electrochemically, by Bolton in 1905.

Atomic number	-	73		Density	g/mL	16	.6
Atomic weight	u	180	.9479	Melting point	K	3287
Bonding radius	A	1	.34	Boiling point	K	5731
Atomic radius	A	2	.09	Heat of vaporization	kJ/mol	743
Ionization Potential	V	7	.89	Heat of fusion	kJ/mol	31	.6
Electronegativity	-	1	.5	Specific heat	J/gK	0	.14
The oxide is mildly acidic.				Crystal are body centered cubic.
Electron config. : [Xe] 4f¹⁴ 5d³ 6s²

Isotopes of Hf(Tantalum) :

MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	156 0.11 sec EC/p,1.029 Hf-156/Hf-155 155.97165	157 5.3 msec a,6.380 MeV Lu-153 156.96811	158 36.8 msec a/EC,6.210 Lu-154/Hf-158 157.96639	159 0.57 sec a/EC,5.750 Lu-155/Hf-159 158.96296
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	160 1.55 sec a/EC,9.900 Lu-156/Hf-160 159.96135	161 3.00 sec a/EC,7.490 Lu-157/Hf-161 160.95837	162 3.60 sec a/EC,9.260 Lu-158/Hf-162 161.95714	163 11.0 sec a/EC,6.800 Lu-159/Hf-163 162.95432
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	164 14.2 sec EC,8.500 MeV Hf-164 163.95362	165 31.0 sec EC,5.800 MeV Hf-165 164.95082	166 31.5 sec EC,7.700 MeV Hf-166 165.95050	167 1.33 min EC,5.000 MeV Hf-167 166.94793
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	168 2.0 min EC,6.700 MeV Hf-168 167.94782	169 4.9 min EC,4.440 MeV Hf-169 168.94591	170 6.76 min EC,6.000 MeV Hf-170 169.94608	171 23.3 min EC,3.700 MeV Hf-171 170.94445
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	172 36.8 min EC,4.920 MeV Hf-172 171.94474	173 3.14 hr EC,2.790 MeV Hf-173 172.94364	174 1.05 hr EC,3.850 MeV Hf-174 173.94416	175 10.5 hr EC,2.000 MeV Hf-175 174.94364
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	176 8.09 hr EC,3.110 MeV Hf-176 175.94474	177 56.56 hr EC,1.166 MeV Hf-177 176.94447	178 9.31 min EC,1.910 MeV Hf-178 177.94575	179 1.82 yr EC,1.106 MeV Hf-179 178.94593
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	180 8.152 hr B-/EC,1.141 W-180/Hf-180 179.94746	181 99.988% Stable 180.94799	182 114.43 da B-,1.814 MeV W-182 181.95015	183 5.1 da B-,1.070 MeV W-183 182.95137
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	184 8.7 hr B-,2.870 MeV W-184 183.95400	185 49.4 min B-,1.992 MeV W-185 184.95555	186 10.5 min B-,3.900 MeV W-186 185.95855

url: www.digitalexandria.com | mail:
Web Engineering: Alessandro Tugnoli, Alessandro Yoshi Polliotti, Daniele De Matteis | Graphic Design: Daniele De Matteis []
© 2003-2006 digitAlexandria