Dubnium 105

Atomic No. Order:

Alphabetic Order:

Periodic Table

Algorythm ground state

2, 8, 18, 32,

32, 11, 2

V
23

Nb
41

Ta
73

Db
105

Upp
155

Bnp
205

Dubnium

Symbol

Atomic Number

105

Relative Atomic Mass
¹²C = 12.0000

[268 ]
268.1255

Significant Atomic Mass

268
Neutrons 163

Atomic Radius pm

139 (est.)

First Ionisation Energy
kJ mol ^-1

640 (est.)

Electronegativity

Density kg m ^-3

39000

Molar Volume cm ³

Thermal Conductivity
W m ^-1 K ^-1

Melting Point K

Boiling Point K

Number of Isotopes

256 Db 1.7 s
257 Db 0.8 s
258 Db 4.4 s
259 Db 0.51 s
260 Db 1.5 s
262 Db 35 s
263 Db 29 s
267 Db 1.2 h
268 Db 1.2 d / 0.7d

Inner + outer Shells

Inner + outer Orbitals

105

Filling Orbital

6d ³

Ground State Electron Configuration

[Rn]

5f ¹⁴

6d ³

7s ²

Ground State Electron Configuration with
free Orbitals (n=13)

0, 0, 0, 0, 0, 7, 6

Ground State Electron Configuration with compressed Orbitals (n=162)

0, 0, 0, 0, 18, 54, 90

Singularity

280

162

	s	p	d		f	g	h	i	j
1	2
2	2	6
3	2	6	10
4	2	6	10		14
5	2	6	10		14	18
6	2	6	3	7	14	18	22
7	2	6	10		14	18	22	26
8

Term Symbol

⁴F _3/2

CAS Reg-ID:

53850-35-4

²⁶⁰Db and ²⁶¹Db were initially reported by a group of scientists at Dubna, Russia
G.N.Flerov 1967.

The name preferred by the Russians was
"nielsbohrium, Ns".

²²₁₀Ne + ²⁴³₉₅Am → ²⁶²₁₀₅Db + 3 ¹₀n

Discovery confirmed at Berkeley, USA in 1970. (Ghiorso, Nurmia, Haris, Eskola) (HILAC).

The name preferred by the Americans was " hahnium, Hn" named after Otto Hahn.

¹⁵₇N + ²⁵⁰₉₈Cf → ²⁶¹₁₀₅Db + 4 ¹n

¹⁶₈O + ²⁴⁹₉₇Bk → ²⁶¹₁₀₅Db + 4 ¹n

In 1994, the IUPAC proposed " joliotium, Jl" named after
Jean-Fredeic Joliot and Mme. Joliot-Curie
Finally in 1997, the name was agreed to dubnium, Db

Obsolete Names

Unnilpentium, Unp
eka-tantalum
Hahnium, Hn
Nielsbohrium, Ns
joliotium, Jl

Name derived from

Named after Dubna

To avoid confusion in the literature, when a name has been in unofficial use for a particular element, but a different name is ultimately chosen for a element, then the first name cannot be transferred for another element. A case in point is element 105 for wich the name hahnium has been unofficially used. Since the name dubnium was chosen for that element, hahnium cannot be used for another as yet unnamed element.

APSIDIUM	Created:		2002-09-01		105.pdf
	Page update:		2006-11-05		105.pdf