Roentgenium (Rg)

Roentgenium is the 111th element in the periodic table and has a symbol of Rg and atomic number of 111. It has an atomic weight of (281) and a mass number of 272. Roentgenium has one hundred eleven protons and one hundred sixty-one neutrons in its nucleus, and one hundred eleven electrons in seven shells. It is located in group eleven, period seven and block d of the periodic table.

Atomic Number	111
Atomic Weight	281
Mass Number	272

Group	11
Period	7
Block	d

Protons	111 p⁺
Neutrons	161 n⁰
Electrons	111 e^-

Properties

Physical Properties
Atomic Radius
Molar Volume
Covalent Radius	121 pm 116 pm 118 pm
Metallic Radius
Ionic Radius
Crystal Radius
Van der Waals Radius
Density	28.7 g/cm³
Energy
Proton Affinity
Electron Affinity
Ionization Energy
Heat of Vaporization
Heat of Fusion
Heat of Formation
Electrons
Electron Shells	2, 8, 18, 32, 32, 17, 2

Valence Electrons	2
Electron Configuration	[Rn] 5f¹⁴ 6d⁹ 7s²

Oxidation States
Electronegativity
Electrophilicity
Phases
Phase	Solid
Gas Phase
Boiling Point
Melting Point
Critical Pressure
Critical Temperature
Triple Point
Visual
Roentgenium is a Colorless.
Color	Colorless
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 Roentgenium 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 Roentgenium is IB. The IUPAC Group of Rg is IB. The Mendeleev Number of Element 111 is 74. The Goldschmidt Class of Roentgenium (Rg) is synthetic.
Category	Transition metals, Transition metals
CAS Group	IB
IUPAC Group	IB
Glawe Number
Mendeleev Number	74
Pettifor Number
Geochemical Class
Goldschmidt Class	synthetic
Other
The Dipole Polarizability of Roentgenium is 32 plus or minus 6 a₀. The Allotropes of Rg is . The Quantum Numbers of Element 111 is 2S1/2. The Space Group of Roentgenium (Rg) is ().
Gas Basicity
Dipole Polarizability	32 ± 6 a₀
C6 Dispersion Coefficient
Allotropes
Neutron Cross Section
Neutron Mass Absorption
Quantum Numbers	2S1/2
Space Group	()

Isotopes of Roentgenium

Stable Isotopes	0
Unstable Isotopes	15
Radioactive Isotopes	15

²⁷²Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	272.153273 ± 0.000251 Da
Mass Number	272
G-Factor
Half Life	4.2 ± 1.1 ms
Spin
Quadrupole Moment
Discovery Year	1995
Parity

²⁷²Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁷³Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	273.153393 ± 0.000429 Da
Mass Number	273
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁷³Rg Decay Modes

Decay Mode	Intensity
α (α emission)	%

²⁷⁴Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	274.155247 ± 0.000225 Da
Mass Number	274
G-Factor
Half Life	20 ± 11 ms
Spin
Quadrupole Moment
Discovery Year	2004
Parity

²⁷⁴Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁷⁵Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	275.156088 ± 0.000479 Da
Mass Number	275
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁷⁵Rg Decay Modes

Decay Mode	Intensity
α (α emission)	%

²⁷⁶Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	276.158226 ± 0.000675 Da
Mass Number	276
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁷⁶Rg Decay Modes

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

²⁷⁷Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	277.159322 ± 0.000504 Da
Mass Number	277
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁷⁷Rg Decay Modes

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

²⁷⁸Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	278.16159 ± 0.000417 Da
Mass Number	278
G-Factor
Half Life	8 ± 5 ms
Spin
Quadrupole Moment
Discovery Year	2007
Parity

²⁷⁸Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁷⁹Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	279.16288 ± 0.000453 Da
Mass Number	279
G-Factor
Half Life	170 ± 110 ms
Spin
Quadrupole Moment
Discovery Year	2004
Parity

²⁷⁹Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁸⁰Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	280.165204 ± 0.000571 Da
Mass Number	280
G-Factor
Half Life	4.3 ± 0.5 s
Spin
Quadrupole Moment
Discovery Year	2004
Parity

²⁸⁰Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁸¹Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	281.166757 ± 0.000831 Da
Mass Number	281
G-Factor
Half Life	19 ± 5 s
Spin
Quadrupole Moment
Discovery Year	2010
Parity

²⁸¹Rg Decay Modes

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

²⁸²Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	282.169343 ± 0.000631 Da
Mass Number	282
G-Factor
Half Life	130 ± 50 s
Spin
Quadrupole Moment
Discovery Year	2010
Parity

²⁸²Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%

²⁸³Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	283.171101 ± 0.000728 Da
Mass Number	283
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁸³Rg Decay Modes

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

²⁸⁴Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	284.173882 ± 0.000537 Da
Mass Number	284
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁸⁴Rg Decay Modes

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

²⁸⁵Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	285.175771 ± 0.000644 Da
Mass Number	285
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year
Parity

²⁸⁵Rg Decay Modes

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

²⁸⁶Rg

Abundance	Radioactive ☢️
Relative Atomic Mass	286.178756 ± 0.000492 Da
Mass Number	286
G-Factor
Half Life
Spin
Quadrupole Moment
Discovery Year	2016
Parity

²⁸⁶Rg Decay Modes

Decay Mode	Intensity
α (α emission)	100%
SF (spontaneous fission)	%

History

Roentgenium was first synthesized by an international team led by Sigurd Hofmann at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung) in Darmstadt, Germany in 1994. The team bombarded a target of bismuth-209 with accelerated nuclei of nickel-64 and detected a single atom of the isotope roentgenium-272. Named after Wilhelm Conrad Röntgen, the German physicist

Discoverers	Heavy Ion Research Laboratory (HIRL)
Discovery Location	Germany
Discovery Year	1994
Etymology (Name Origin)	Named in honor of the physicist Wilhelm Roentgen.
Pronunciation	oon-nun-OON-i-em (English)

Roentgenium is harmful due to its radioactivity

Roentgenium has no stable or naturally-occurring isotopes

Uses

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

Sources

Made by bombarding bismuth-209 with nickel-60.

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

Roentgenium on ChemicalAid

Australian Educational Vocabulary ID	scot/9704
CAS Registry Number	54386-24-2
Elhuyar ZTH ID	133475
Encyclopædia Britannica Online ID	science/roentgenium
Freebase ID	/m/025tpyw
GND ID	7635623-1
Gran Enciclopèdia Catalana ID	0282399
Great Russian Encyclopedia Online ID	3505864
KBpedia ID	Roentgenium
Library of Congress authority ID	sh2012003700
NE.se ID	röntgenium
NE.se ID	unununium
National Library of Israel J9U ID	987007595444605171
OmegaWiki Defined Meaning	350608
Online PWN Encyclopedia ID	4005803
Store norske leksikon ID	røntgenium
USGS Thesaurus ID	1602
WordNet 3.1 Synset ID	14677003-n

Roentgenium (Rg)

Properties

Isotopes of Roentgenium

272Rg

272Rg Decay Modes

273Rg

273Rg Decay Modes

274Rg

274Rg Decay Modes

275Rg

275Rg Decay Modes

276Rg

276Rg Decay Modes

277Rg

277Rg Decay Modes

278Rg

278Rg Decay Modes

279Rg

279Rg Decay Modes

280Rg

280Rg Decay Modes

281Rg

281Rg Decay Modes

282Rg

282Rg Decay Modes

283Rg

283Rg Decay Modes

284Rg

284Rg Decay Modes

285Rg

285Rg Decay Modes

286Rg

286Rg Decay Modes