U - Uranium

Uranium oxide has been used since Roman times for yellow pigments in glass. The element was discovered in 1789 by a German chemist, Martin Klaproth, who named it for the newly observed seventh planet. In 1841, French chemist Eugene Peligot extracted pure uranium metal, which caused little interest until March 1, 1869, when French physicist, Henry Becquerel serendipidously discovered radioactivity in uranium salts - suddenly uranium was hot stuff!

Although only mildly radioactive, uranium compounds are toxic.

Atomic number - 92 Density g/mL 18 .9
Atomic weight u 238 .029 Melting point K 1405
Bonding radius A 1 .42 Boiling point K 4407
Atomic radius A - Heat of vaporization kJ/mol 477
Ionization Potential V 6 .05 Heat of fusion kJ/mol 8 .52
Electronegativity - 1 .38 Specific heat J/gK 0 .12
The oxide is amphoteric.
Crystal are orthorhombic.

Electron config. : [Rn] 5f3 6d1 7s2

Isotopes of U: Click mass number for decay process, product for element page.


218
1.5 msec
a,8.790 MeV
Th-214
218.02348
219
42 usec
a,9.900 MeV
Th-215
219.02495
222
1.0 usec
a,9.500 MeV
Th-218
222.02606
223
18 usec
a,8.940 MeV
Th-219
223.02771
224
0.9 msec
a,8.620 MeV
Th-220
224.02759
225
95 msec
a,8.020 MeV
Th-221
225.02938
226
200 msec
a,7.715 MeV
Th-222
226.02933
227
1.1 min
a,7.211 MeV
Th-223
227.03113
228
9.1 min
a/EC,6.804
Th-224/Pa-228
228.03136
229
58 min
a/EC,1.309
Th-225/Pa-229
229.03349
230
20.8 da
a,5.993 MeV
Th-226
230.03392
231
4.2 da
a/EC,5.149
Th-227/Pa-231
231.03626
232
68.9 yr
a/Ne,5.414
Th-228/?
232.03714
233
1.592E+5 yr
a/Ne/SF,4.909
Th-229/?/?
233.03962
234 0.0055%
2.455E+5 yr
a/SF,4.859
Th-230/?
234.04094
235 0.720%
703.8E+6 yr
a/Ne/SF,4.679
Th-231/?/?
235.04392
236
2.342E7 yr
a/SF,4.572
Th-232/?
236.04556
237
6.75 da
B-,2.250 MeV
Np-237
237.04872
238 99.2745%
4.468E+9 yr
a/SF,4.270
Th-234/?
238.05078
239
23.45 min
B-,1.265 MeV
Np-239
239.05428
240
14.1 hr
B-,3.900 MeV
Np-240
240.05658
242
16.8 min
B-,7.660 MeV
Np-242
242.06315
MASS abund.
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass