Dubnium (Db)

Dubnium is the 105th element in the periodic table and has a symbol of Db and atomic number of 105. It has an atomic weight of (268) and a mass number of 255. Dubnium has one hundred five protons and one hundred fifty neutrons in its nucleus, and one hundred five electrons in seven shells. It is located in group five, period seven and block d of the periodic table. Also known as Hahnium, Ha. Radioactive transactinide element. Half-life of 1.6s. Discovered in 1970 by Berkeley researchers. So far, seven isotopes have been discovered.

Atomic Number	105
Atomic Weight	268
Mass Number	255

Group	5
Period	7
Block	d

Protons	105 p⁺
Neutrons	150 n⁰
Electrons	105 e^-

Properties

Physical Properties
Atomic Radius
Molar Volume
Covalent Radius	149 pm 136 pm 126 pm
Metallic Radius
Ionic Radius
Crystal Radius
Van der Waals Radius
Density	29.3 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy	6.8 eV/particle 14 eV/particle 23.1 eV/particle 33 eV/particle 43 eV/particle 86 eV/particle 98.9 eV/particle 126 eV/particle 145 eV/particle 172 eV/particle 196 eV/particle 220.9 eV/particle 254 eV/particle 274 eV/particle 307 eV/particle 838 eV/particle 872 eV/particle 908 eV/particle 948 eV/particle 985 eV/particle 1,022 eV/particle 1,089 eV/particle 1,126 eV/particle 1,168 eV/particle 1,207 eV/particle 3,975 eV/particle 4,057 eV/particle 4,145 eV/particle 4,237 eV/particle 4,326 eV/particle 4,411 eV/particle 4,620 eV/particle 4,710 eV/particle 4,810 eV/particle 4,900 eV/particle 5,260 eV/particle 5,350 eV/particle 5,450 eV/particle 5,530 eV/particle 6,280 eV/particle 6,380 eV/particle 6,650 eV/particle 6,760 eV/particle 10,420 eV/particle 10,610 eV/particle 10,820 eV/particle 11,040 eV/particle 11,240 eV/particle 11,440 eV/particle 12,040 eV/particle 12,250 eV/particle 12,480 eV/particle 12,700 eV/particle 13,300 eV/particle 13,500 eV/particle 13,700 eV/particle 13,900 eV/particle 16,200 eV/particle 16,400 eV/particle 16,900 eV/particle 17,100 eV/particle 33,800 eV/particle 34,300 eV/particle 34,800 eV/particle 35,300 eV/particle 43,800 eV/particle 44,500 eV/particle 45,400 eV/particle 181,444 eV/particle

Heat of Vaporization
Heat of Fusion
Heat of Formation
Electrons
Electron Shells	2, 8, 18, 32, 32, 11, 2

Valence Electrons	2
Electron Configuration	[Rn] 5f¹⁴ 6d³ 7s²

Oxidation States	5
Electronegativity
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point
Melting Point
Critical Pressure
Critical Temperature
Triple Point
Visual
Dubnium is a Colorless. Db has a Jmol of #d1004f.
Color	Colorless #d1004f
Appearance
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion
Molar Heat Capacity
Specific Heat Capacity
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type
Electrical Conductivity
Electrical Resistivity
Superconducting Point
Magnetism
Type
Magnetic Susceptibility (Mass)
Magnetic Susceptibility (Molar)
Magnetic Susceptibility (Volume)
Magnetic Ordering
Curie Point
Neel Point
Structure
The lattice angles of Dubnium is .
Crystal Structure	()
Lattice Constant
Lattice Angles
Mechanical Properties

Hardness
Bulk Modulus
Shear Modulus
Young Modulus
Poisson Ratio
Speed of Sound
Classification
The CAS Group of Dubnium is VA. The IUPAC Group of Db is VB. The Mendeleev Number of Element 105 is 50. The Goldschmidt Class of Dubnium (Db) is synthetic.
Category	Transition metals, Transition metals
CAS Group	VA
IUPAC Group	VB
Glawe Number
Mendeleev Number	50
Pettifor Number
Geochemical Class
Goldschmidt Class	synthetic
Other
The Dipole Polarizability of Dubnium is 42 plus or minus 4 a₀. The Allotropes of Db is . The Quantum Numbers of Element 105 is 4F3/2. The Space Group of Dubnium (Db) is ().
Gas Basicity
Dipole Polarizability	42 ± 4 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
Neutron Mass Absorption
Quantum Numbers	4F3/2
Space Group	()

Isotopes of Dubnium

Stable Isotopes	0
Unstable Isotopes	16
Radioactive Isotopes	16

²⁵⁵Db

Abundance	Radioactive ☢️
Relative Atomic Mass	255.106919 ± 0.000304 Da
Mass Number	255
G-Factor
Half Life	54 ms
Spin	9/2
Quadrupole Moment
Discovery Year	1976
Parity	+

²⁵⁵Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	67%
α (α emission)	%

²⁵⁶Db

Abundance	Radioactive ☢️
Relative Atomic Mass	256.107674 ± 0.000201 Da
Mass Number	256
G-Factor
Half Life	1.7 ± 0.4 s
Spin	9
Quadrupole Moment
Discovery Year	2001
Parity	-

²⁵⁶Db Decay Modes

Decay Mode	Intensity
α (α emission)	70%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	30%
SF (spontaneous fission)	%

²⁵⁷Db

Abundance	Radioactive ☢️
Relative Atomic Mass	257.107520042 ± 0.000176741 Da
Mass Number	257
G-Factor
Half Life	2.3 ± 0.2 s
Spin	9/2
Quadrupole Moment
Discovery Year	1985
Parity	+

²⁵⁷Db Decay Modes

Decay Mode	Intensity
α (α emission)	94%
SF (spontaneous fission)	6%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁵⁸Db

Abundance	Radioactive ☢️
Relative Atomic Mass	258.108972995 ± 0.000098613 Da
Mass Number	258
G-Factor	0
Half Life	2.17 ± 0.36 s
Spin	0
Quadrupole Moment	0
Discovery Year	1985
Parity	-

²⁵⁸Db Decay Modes

Decay Mode	Intensity
α (α emission)	64%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	36%

²⁵⁹Db

Abundance	Radioactive ☢️
Relative Atomic Mass	259.109491859 ± 0.000060854 Da
Mass Number	259
G-Factor
Half Life	510 ± 160 ms
Spin	9/2
Quadrupole Moment
Discovery Year	2001
Parity	+

²⁵⁹Db Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁶⁰Db

Abundance	Radioactive ☢️
Relative Atomic Mass	260.111297 ± 0.0001 Da
Mass Number	260
G-Factor
Half Life	1.52 ± 0.13 s
Spin
Quadrupole Moment
Discovery Year	1970
Parity

²⁶⁰Db Decay Modes

Decay Mode	Intensity
α (α emission)	90.4%
SF (spontaneous fission)	9.6%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁶¹Db

Abundance	Radioactive ☢️
Relative Atomic Mass	261.111979 ± 0.000118 Da
Mass Number	261
G-Factor
Half Life	4.7 ± 1 s
Spin	9/2
Quadrupole Moment
Discovery Year	1970
Parity	+

²⁶¹Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	73%
α (α emission)	27%

²⁶²Db

Abundance	Radioactive ☢️
Relative Atomic Mass	262.114067 ± 0.000154 Da
Mass Number	262
G-Factor
Half Life	34 ± 4 s
Spin
Quadrupole Moment
Discovery Year	1971
Parity

²⁶²Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	52%
α (α emission)	48%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁶³Db

Abundance	Radioactive ☢️
Relative Atomic Mass	263.114987 ± 0.00018 Da
Mass Number	263
G-Factor
Half Life	29 ± 9 s
Spin	9/2
Quadrupole Moment
Discovery Year	1992
Parity	+

²⁶³Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	56%
α (α emission)	37%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	6.9%

²⁶⁴Db

Abundance	Radioactive ☢️
Relative Atomic Mass	264.117297 ± 0.000253 Da
Mass Number	264
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁶⁴Db Decay Modes

Decay Mode	Intensity
α (α emission)	%

²⁶⁵Db

Abundance	Radioactive ☢️
Relative Atomic Mass	265.1185 ± 0.00024 Da
Mass Number	265
G-Factor
Half Life
Spin	9/2
Quadrupole Moment
Discovery Year
Parity	+

²⁶⁵Db Decay Modes

Decay Mode	Intensity
α (α emission)	%

²⁶⁶Db

Abundance	Radioactive ☢️
Relative Atomic Mass	266.121032 ± 0.000304 Da
Mass Number	266
G-Factor
Half Life	80 ± 70 m
Spin
Quadrupole Moment
Discovery Year	2007
Parity

²⁶⁶Db Decay Modes

Decay Mode	Intensity
α (α emission)	%
SF (spontaneous fission)	%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

²⁶⁷Db

Abundance	Radioactive ☢️
Relative Atomic Mass	267.122399 ± 0.000402 Da
Mass Number	267
G-Factor
Half Life	2 ± 1.1 h
Spin	9/2
Quadrupole Moment
Discovery Year	2004
Parity	+

²⁶⁷Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	100%

²⁶⁸Db

Abundance	Radioactive ☢️
Relative Atomic Mass	268.125669 ± 0.000568 Da
Mass Number	268
G-Factor
Half Life	29 ± 3 h
Spin
Quadrupole Moment
Discovery Year	2004
Parity

²⁶⁸Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	100%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
α (α emission)	%

²⁶⁹Db

Abundance	Radioactive ☢️
Relative Atomic Mass	269.127911 ± 0.000669 Da
Mass Number	269
G-Factor
Half Life
Spin	9/2
Quadrupole Moment
Discovery Year
Parity	+

²⁶⁹Db Decay Modes

Decay Mode	Intensity
α (α emission)	%
SF (spontaneous fission)	%

²⁷⁰Db

Abundance	Radioactive ☢️
Relative Atomic Mass	270.131399 ± 0.000617 Da
Mass Number	270
G-Factor
Half Life	1.7 ± 1 h
Spin
Quadrupole Moment
Discovery Year	2010
Parity

²⁷⁰Db Decay Modes

Decay Mode	Intensity
SF (spontaneous fission)	87%
α (α emission)	13%

History

Dubnium was reportedly first discovered in 1968 at the Joint Institute for Nuclear Research at Dubna. Researchers there bombarded an americium-243 target with neon-22 ions. In the same year, a team led by Albert Ghiorso working at the University of California, Berkeley conclusively synthesized the element by bombarding a californium-249 target with nitrogen-15 ions. Named after the Russian town of Dubna

Discoverers	A. Ghiorso, et al
Discovery Location	United States
Discovery Year	1970
Etymology (Name Origin)	Named after the city of Dubna, the site of the JINR.
Pronunciation	HA-ni-em (English)

Dubnium is harmful due to its radioactivity

The Berkeley team proposed the name hahnium for the element

Uses

Dubnium is used for scientific research purposes only. It has no significant commercial applications.

Sources

Made by bombarding californium-249 with a beam of nitrogen-15

Abundance
Abundance in Earth's crust
Abundance in Oceans
Abundance in Human Body	0 %
Abundance in Meteor	0 %
Abundance in Sun	0 %
Abundance in Universe	0 %

Nuclear Screening Constants

Dubnium on ChemicalAid

Australian Educational Vocabulary ID	scot/3514
CAS Registry Number	53850-35-4
DSSTOX compound identifier	DTXCID801323011
DSSTox substance ID	DTXSID30893063
Den Store Danske ID	dubnium
ECHA Substance Infocard ID	100.126.367
Elhuyar ZTH ID	064402
Encyclopedia of China (Third Edition) ID	185643
Encyclopædia Britannica Online ID	science/dubnium
Freebase ID	/m/0274b33
GND ID	4293095-9
Gran Enciclopèdia Catalana ID	0272492
Great Russian Encyclopedia Online ID	1969523
KBpedia ID	Dubnium
NKCR AUT ID	ph928215
OmegaWiki Defined Meaning	157650
Store norske leksikon ID	dubnium
Treccani ID	dubnio
USGS Thesaurus ID	1442

Dubnium (Db)

Properties

Isotopes of Dubnium

255Db

255Db Decay Modes

256Db

256Db Decay Modes

257Db

257Db Decay Modes

258Db

258Db Decay Modes

259Db

259Db Decay Modes

260Db

260Db Decay Modes

261Db

261Db Decay Modes

262Db

262Db Decay Modes

263Db

263Db Decay Modes

264Db

264Db Decay Modes

265Db

265Db Decay Modes

266Db

266Db Decay Modes

267Db

267Db Decay Modes

268Db

268Db Decay Modes

269Db

269Db Decay Modes

270Db

270Db Decay Modes