Dubny

Dubny
Dubny
	← Rutherfordium \| Seaborgium →
	105 db
	105 db
The appearance of a simple substance
	Unknown, presumably silver-white metal
Atom properties
Name, symbol, number	Dubna (Db), 105
Atomic mass; ( molar mass )	268 a. E. m. ( g / mol )
Electronic configuration	[Rn] 5f 14 6d 3 7s 2
Chemical properties
Oxidation state	+3, +4, +5
Thermodynamic properties of a simple substance
Density (at N. at. )	21.6 g / cm³
CAS Number

Dubny (Db), until 1997 in the USSR and Russia is known as nilsbory (Ns) - the 105th element of the periodic table .

105	Dubny
Db (270)
5f ¹⁴ 6d ³ 7s ²

Content

History

Element 105 was first obtained at the accelerator in Dubna in 1970 by the group of G. N. Flerov by bombarding ²⁴³ Am nuclei with ²² Ne ions ^[1] and independently in Berkeley ( USA ) in the reaction ²⁴⁹ Cf + ¹⁵ N → ²⁶⁰ Db + 4n ^[2] . The IUPAC working group in 1993 concluded that the honor of opening element 105 should be shared between groups from Dubna and Berkeley ^[3] .

Name Origin

Soviet researchers proposed calling the new element nilsborium (Ns), in honor of Niels Bohr ^[4] , Americans - ganium (Ha), in honor of Otto Gan , one of the authors of the discovery of spontaneous uranium fission ^[2] . The IUPAC Commission in 1994 proposed the name Joliotius (Jl), in honor of Joliot-Curie ^[5] ; before that, the element was officially called the Latin numeral - unnilpentium (Unp), that is, simply the 105th. Symbols Ns, Na, Jl could be seen in the tables of elements published in different years. According to the final decision of IUPAC in 1997, this element was called dubnium - in honor of the Russian center for research in the field of nuclear physics, the science city of Dubna ^[6] .

Known Isotopes

Isotope	Weight	Half-life ^[7]	Decay type
²⁵⁵ db	255	$1{,}6\,_{-0,4}^{+0,6}$ ${\ displaystyle 1 {,} 6 \, _ {- 0.4} ^ {+ 0.6}}$ with	α decay at ²⁵¹ Lr (80%); spontaneous division
²⁵⁶ db	256	$1{,}6\,_{-0,3}^{+0,5}$ ${\ displaystyle 1 {,} 6 \, _ {- 0.3} ^ {+ 0.5}}$ with	α decay at ²⁵² Lr (64%); β decay at ²⁵⁶ Rf (36%); spontaneous division (0.02%)
²⁵⁷ db	257	$1{,}50\,_{-0,15}^{+0,19}$ ${\ displaystyle 1 {,} 50 \, _ {- 0.15} ^ {+ 0.19}}$ with	α decay at ²⁵³ Lr
²⁵⁸ db	258	4.0 ± 1.0 s	α decay at ²⁵⁴ Lr (67%); β decay at ²⁵⁸ Rf
²⁵⁹ db	259	0.51 ± 0.16 s	α decay at ²⁵⁵ Lr
²⁶⁰ db	260	1.52 ± 0.13 s	α decay at ²⁵⁶ Lr
²⁶¹ db	261	1.8 ± 0.4 s	α decay at ²⁵⁷ Lr
²⁶² db	262	35 ± 5 s	α decay at ²⁵⁸ Lr (67%); spontaneous division
²⁶³ db	263	$27\,_{-07}^{+10}$ ${\ displaystyle 27 \, _ {- 07} ^ {+ 10}}$ with	spontaneous division (55%); α decay at ²⁵⁹ Lr (41%); β decay at ²⁶³ Rf (3%)
²⁶⁷ db	267	$73\,_{-033}^{+350}$ ${\ displaystyle 73 \, _ {- 033} ^ {+ 350}}$ min	spontaneous division
²⁶⁸ db	268	$32\,_{-07}^{+11}$ ${\ displaystyle 32 \, _ {- 07} ^ {+ 11}}$ hours	spontaneous division

Notes

↑ GN Flerov et al. On the synthesis of element 105 // Nuclear Physics A. - 1970. - T. 160 , No. 1 . - S. 181-192 .
↑ ¹ ² Albert Ghiorso et al. New Element Hahnium, Atomic Number 105 // Physical Review Letters . - 1970. - T. 24 , No. 26 . - S. 1498 - 1503 .
↑ RC Barber et al. Discovery of the transfermium elements // Pure and Applied Chemistry . - 1993. - T. 65 , No. 8 . - S. 1757-1814 .
↑ See, for example, GN Flerov and GM Ter-Akopian. Synthesis and study of atomic nuclei with Z> 100 // Progress in Particle and Nuclear Physics . - 1987.- T. 19 . - S. 197-239 .
↑ Commission on Nomenclature of Inorganic Chemistry. Names and symbols of transfermium elements (IUPAC Recommendations 1994) // Pure and Applied Chemistry . - 1994. - T. 66 , No. 12 . - S. 2419-2421 .
↑ Commission on Nomenclature of Inorganic Chemistry. Names and symbols of transfermium elements (IUPAC Recommendations 1997) // Pure and Applied Chemistry . - 1997. - T. 69 , No. 12 . - S. 2471-2473 .
↑ Nudat 2.3

Links

[fl1970-1] GN Flerov et al. On the synthesis of element 105 // Nuclear Physics A. - 1970. - T. 160 , No. 1 . - S. 181-192 .

[gh1970-2] ¹ ² Albert Ghiorso et al. New Element Hahnium, Atomic Number 105 // Physical Review Letters . - 1970. - T. 24 , No. 26 . - S. 1498 - 1503 .

[iupac1993-3] RC Barber et al. Discovery of the transfermium elements // Pure and Applied Chemistry . - 1993. - T. 65 , No. 8 . - S. 1757-1814 .

[fl1987-4] See, for example, GN Flerov and GM Ter-Akopian. Synthesis and study of atomic nuclei with Z> 100 // Progress in Particle and Nuclear Physics . - 1987.- T. 19 . - S. 197-239 .

[iupac1994-5] Commission on Nomenclature of Inorganic Chemistry. Names and symbols of transfermium elements (IUPAC Recommendations 1994) // Pure and Applied Chemistry . - 1994. - T. 66 , No. 12 . - S. 2419-2421 .

[iupac1997-6] Commission on Nomenclature of Inorganic Chemistry. Names and symbols of transfermium elements (IUPAC Recommendations 1997) // Pure and Applied Chemistry . - 1997. - T. 69 , No. 12 . - S. 2471-2473 .

[nudat-7] Nudat 2.3