Mendeleev's Periodic Table > Hf - Hafnium

Hf - Hafnium

The transition element hafnium was discovered by Coster and Hevesey in 1923 in Denmark. Most zirconium minerals contain 1 to 3% hafnium. Hafnium is a ductile metal with a brilliant silver lustre. Its properties are influenced considerably by the impurities of zirconium present. Of all the elements, zirconium and hafnium are two of the most difficult to separate. Hafnium is a Group 4 transition element. Because hafnium has a good absorption cross section for thermal neutrons (almost 600 times that of zirconium), has excellent mechanical properties, and is extremely corrosion resistant, it is used for nuclear reactor control rods. Hafnium carbide is the most refractory binary composition known, and the nitride is the most refractory metal nitride (m.p. 3310°C).

Atomic number	-	72		Density	g/mL	13	.1
Atomic weight	u	178	.49	Melting point	K	2500
Bonding radius	A	1	.44	Boiling point	K	4876
Atomic radius	A	2	.16	Heat of vaporization	kJ/mol	575
Ionization Potential	V	6	.65	Heat of fusion	kJ/mol	24	.06
Electronegativity	-	1	.3	Specific heat	J/gK	0	.14
The oxide is amphoteric.				Crystal are hexagonal.
Electron config. : [Xe] 4f¹⁴ 5d² 6s²

Isotopes of Hf (Hafnium) :

MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	154 2 sec a/EC,6.700 Yb-150/Lu-154 153.96425	155 0.89 sec a/EC,8.000 Yb-151/Lu-155 154.96274	156 25 msec a,6.033 MeV Yb-152 155.95920	157 110 msec a/EC,5.880 Yb-153/Lu-157 156.95813
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	158 2.86 sec a/EC,5.100 Yb-154/Lu-158 157.95464	159 5.6 sec a/EC,6.700 Yb-155/Lu-159 158.95383	160 13.6 sec a/EC,4.370 Yb-156/Lu-160 159.95071	161 16.8 sec a/EC,6.300 Yb-157/Lu-161 160.95032
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	162 37.6 sec a/EC,3.450 Yb-158/Lu-162 161.94720	163 40.0 sec EC,5.500 MeV Lu-163 162.94707	164 111 sec EC,2.970 MeV Lu-164 163.94442	165 76 sec EC,4.600 MeV Lu-165 164.94449
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	166 6.77 min EC,2.300 MeV Lu-166 165.94224	167 2.05 min EC,4.000 MeV Lu-167 166.94259	168 25.95 min EC,1.800 MeV Lu-168 167.94063	169 3.24 min EC,3.270 MeV Lu-169 168.94115
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	170 16.01 hr EC,1.100 MeV Lu-170 169.93964	171 12.1 hr EC,2.400 MeV Lu-171 170.94049	172 1.87 yr EC,8.600 MeV Lu-172 171.93946	173 23.6 hr EC,1.610 MeV Lu-173 172.94065
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	174 0.162% 2.0E15 yr a,2.495 MeV Yb-170 173.94004	175 70 da EC,6.782 MeV Lu-175 174.94150	176 5.206% Stable 175.94140	177 18.606% Stable 176.94322
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	178 27.297% Stable 177.94369	179 13.629% Stable 178.94581	180 35.100% B-Stable Ta-180 179.94654	181 42.39 da B-,1.027 MeV Ta-181 180.94909
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	182 9E+6 yr B-,9.300 MeV Ta-182 181.95055	183 1.067 hr B-,2.010 MeV Ta-183 182.95352	184 4.12 hr B-,1.340 MeV Ta-184 183.95544	184a 48 sec B-,1.340 MeV Ta-184 183.95544
MASS abundancy Halflife Particle, Energy Decay Product(s) Isotopic Mass	185 3.5 min B-,6.000 MeV Ta-185 184.95902

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