WebElements Periodic Table of the Elements | Dubnium

Dubnium: the essentials

Dubnium is a synthetic element that is not present in the environment at all. It has no uses.

Table: basic information about and classifications of dubnium.
Name: Dubnium Symbol: Db Atomic number: 105 Atomic weight: [ 268 ] Standard state: presumably a solid at 298 K CAS Registry ID: 53850-35-4	Group in periodic table: 5 Group name: (none) Period in periodic table: 7 Block in periodic table: d-block Colour: unknown, but probably metallic and silvery white or grey in appearance Classification: Metallic

Dubnium: historical information

Dubnium was discovered by Workers at the Nuclear Institute at Dubna, and the University of California, Berkeley, USA. at 1967 in USSR, United States. Origin of name: the origin of the name dubnium is the Joint Nuclear Institute at Dubna", an institute heavily involved in the search for heavy elements.

Dubnium apparently was synthesized by Russian and American workers independently by bombardment technologies. Its actual isolation as the free element has not been accomplished. In 1967, Flerov reported element 105 after experiments at the Joint Research Institute in Russia involving reactions between ²⁴³Am ions with ²²Ne ions. In 1970, Ghiorso and others announced their synthesis of dubnium at Berkeley (California) in the USA. This method involved the collsion of ²⁴⁹Cf ions with ¹⁵N ions.

Dubnium: physical properties

Melting point: no data K
Boiling point: no data K
Density of solid: 21600 (predicted) kg m^-3

Ground state electron configuration: [Rn].5f¹⁴.6d³.7s² (a guess based upon that of tantalum)
Shell structure: 2.8.18.32.32.11.2
Term symbol: ⁴F_3/2 (a guess based upon guessed electronic structure)
Pauling electronegativity: no data (Pauling units)
First ionisation energy: no data kJ mol^-1
Second ionisation energy: no data kJ mol^-1

Isolation

Isolation: 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 + 4 ¹n

¹⁶N + ²⁴⁹Bk → ²⁶¹₁₀₅Db + 4 ¹n

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

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Hf	Ta	W
Rf	Db	Sg

Dubnium	Dubnium
Dubnium	Dubnium
Dubnio	Dubnio
Dubnium	Dubnio

Dubnium
- Essential data: names, symbol, atomic number, and atomic weight; block, period, and group in periodic table; description; standard state; registry number; and isolation
- History: meaning of name; discovery; and history of the element
- Uses
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Dubnium around us
- Geology: Abundance of elements in the universe; the sun; meteorites; Earth's crust; oceans; and streams
- Biology: Abundance in humans; biological role; and health hazards)
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Chemistry and compounds
- Compounds: halides, oxides, sulfides, hydrides, and complexes; lattice energies; and reduction potentials
- Reactions of dubnium: reactions of dubnium with air; water; halogens; acids; and bases
- Electronegativities: Pauling; Sanderson; Allred Rochow; Mulliken-Jaffe; and Allen
- Bond enthalpies of diatomic species
- Lattice energies
Element properties
- Physics properties: Boiling point; melting point; density; molar volume; thermal conductivity; and electrical resistivity; bulk modulus; critical temperature; superconductivity temperature; hardness (mineralogical, Brinell, and Vickers); linear expansion coefficient; Poisson's ratio; reflectivity; refractive index; rigidity modulus; Young's modulus; velocity of sound
- Crystal structure
- Thermochemistry: enthalpies of atomization, fusion, and vaporization; thermodynamic properties
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Atom properties
- Electron shell properties: Electronic configuration; term symbol; electron affinity; ionization energies; and atomic spectra
- Atom sizes: atomic radius; Shannon and Pauling ionic radii; covalent radius; metallic radius; element bond length; and Van der Waals radius
- Atomic orbital properties: effective nuclear charge; electron binding energies; and valence orbital radii maxima
Nuclear properties
- Isotopes: isotope abundances; radioactive isotopes; isotope masses; nuclear spins; and nuclear magnetic moment
- NMR properties: frequencies; isotopes; magnetogyric ratios; quadrupole moments; receptivities; and relative sensitivities
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1	2															3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18

1 H																															2 He
3 Li	4 Be																									5 B	6 C	7 N	8 O	9 F	10 Ne
11 Na	12 Mg																									13 Al	14 Si	15 P	16 S	17 Cl	18 Ar
19 K	20 Ca															21 Sc	22 Ti	23 V	24 Cr	25 Mn	26 Fe	27 Co	28 Ni	29 Cu	30 Zn	31 Ga	32 Ge	33 As	34 Se	35 Br	36 Kr
37 Rb	38 Sr															39 Y	40 Zr	41 Nb	42 Mo	43 Tc	44 Ru	45 Rh	46 Pd	47 Ag	48 Cd	49 In	50 Sn	51 Sb	52 Te	53 I	54 Xe
55 Cs	56 Ba	57 La	58 Ce	59 Pr	60 Nd	61 Pm	62 Sm	63 Eu	64 Gd	65 Tb	66 Dy	67 Ho	68 Er	69 Tm	70 Yb	71 Lu	72 Hf	73 Ta	74 W	75 Re	76 Os	77 Ir	78 Pt	79 Au	80 Hg	81 Tl	82 Pb	83 Bi	84 Po	85 At	86 Rn
87 Fr	88 Ra	89 Ac	90 Th	91 Pa	92 U	93 Np	94 Pu	95 Am	96 Cm	97 Bk	98 Cf	99 Es	100 Fm	101 Md	102 No	103 Lr	104 Rf	105 Db	106 Sg	107 Bh	108 Hs	109 Mt	110 Ds	111 Rg	112 Cn	113 Uut	114 Fl	115 Uup	116 Lv	117 Uus	118 Uuo

Dubnium

Dubnium: the essentials

Dubnium: historical information

Dubnium: physical properties

Dubnium: orbital properties

Isolation

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