Mendeleev's Periodic Table > Db - Dubnium

Db - Dubnium

An artifical element. Dubnium was discovered by Ghiorso and coworkers. Named for Dubna, a Russian town north of Moscow that is home to the Joint Institutes of Nuclear Research.
Only very small amounts of of element 105, dubnium, have ever been made. The first samples were made through nuclear reactions involving fusion of an isotope of californium, 249Cf, with one of nitrogen, 14N. A second route to the same isotope via berkelium is also known

15N + 249Cf 261105Db + 41n

16N + 249Bk 261105Db + 41n

Isolation of an observable quantity of dubnium has never been achieved.

Atomic number - 105 Density g/mL -
Atomic weight u 262 Melting point K -
Bonding radius A - Boiling point K -
Atomic radius A - Heat of vaporization kJ/mol -
Ionization Potential V - Heat of fusion kJ/mol -
Electronegativity - - Specific heat J/gK -
The oxide is unknown. Crystal are unknown.
Electron config. : [Rn] 5f14 6d3 7s2

Isotopes of Db (Dubnium):

MASS abundancy
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass		 255
1.6 sec
a/SF,9.600
Lr-251/?
255.0 		256
2.6 sec
a/EC/SF,9.500
Lr-252/Rf-256/?
256.0 		257
1.3 sec
a/EC/SF,9.310
Lr-253/Rf-257/?
257.10789 		258
20 sec
a/EC/SF,5.500
Lr-254/Rf-258/?
258.10939
MASS abundancy
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass		 259

a,2.450 MeV
Lr-255
259.10971 		260
1.52 sec
a/EC/SF,9.370
Lr-256/Rf-260/?
260.11143 		261
1.8 sec
a/SF,9.270
Lr-257/?
261.11207 		262
34 sec
a/EC/SF,9.210
Lr-258/Rf-262/?
262.11437
MASS abundancy
Halflife
Particle, Energy
Decay Product(s)
Isotopic Mass		 263
27 sec
a/SF,9.030
Lr-259/?
263.11528 		264

,9.690 MeV

264.11766 		265

,10.800 MeV

265.11884 		266

,10.820 MeV

266.12131