Osmium (Os)

Osmium is the 76th element in the periodic table and has a symbol of Os and atomic number of 76. It has an atomic weight of 190.23 and a mass number of 192. Osmium has seventy-six protons and one hundred sixteen neutrons in its nucleus, and seventy-six electrons in six shells. It is located in group eight, period six and block d of the periodic table. Hard blue-white metallic transition element. Found with platinum and used in some alloys with platinum and iridium.

Atomic Number	76
Atomic Weight	190.23
Mass Number	192

Group	8
Period	6
Block	d

Protons	76 p⁺
Neutrons	116 n⁰
Electrons	76 e^-

Properties

Physical Properties
Atomic Radius	130 pm 244 pm
Molar Volume	8.43 cm³/mol
Covalent Radius	129 pm 116 pm 109 pm 144 pm
Metallic Radius	126 pm 135 pm
Ionic Radius	63 pm 57.5 pm 49 pm 54.5 pm 52.5 pm 39 pm
Crystal Radius	77 pm 71.5 pm 63 pm 68.5 pm 66.5 pm 53 pm
Van der Waals Radius	200 pm 216 pm 235 pm 312 pm
Density	22.5872 g/cm³ 20,000 kg/m³
Energy
Proton Affinity
Electron Affinity	1.1 eV/particle
Ionization Energy	8.43823 eV/particle 17 eV/particle 25 eV/particle 41 eV/particle 55 eV/particle 70.1 eV/particle 85.1 eV/particle 102.024 eV/particle 168.7 eV/particle 190 eV/particle 213 eV/particle 235 eV/particle 269 eV/particle 300 eV/particle 320 eV/particle 367 eV/particle 410 eV/particle 436 eV/particle 470 eV/particle 520 eV/particle 570 eV/particle 620 eV/particle 670 eV/particle 720 eV/particle 770 eV/particle 820 eV/particle 870 eV/particle 920 eV/particle 970 eV/particle 1,015 eV/particle 1,262 eV/particle 1,311 eV/particle 1,364 eV/particle 1,420 eV/particle 1,474 eV/particle 1,528 eV/particle 1,606 eV/particle 1,660 eV/particle 1,720 eV/particle 1,776 eV/particle 1,996 eV/particle 2,052 eV/particle 2,112 eV/particle 2,168 eV/particle 2,336 eV/particle 2,400 eV/particle 2,552 eV/particle 2,615.5 eV/particle 4,374 eV/particle 4,501 eV/particle 4,635 eV/particle 4,779 eV/particle 4,917 eV/particle 5,052 eV/particle 5,280 eV/particle 5,421 eV/particle 5,575 eV/particle 5,717 eV/particle 6,115 eV/particle 6,240 eV/particle 6,376 eV/particle 6,503 eV/particle 7,039 eV/particle 7,185 eV/particle 7,468 eV/particle 7,610 eV/particle 16,560 eV/particle 16,900 eV/particle 17,270 eV/particle 17,620 eV/particle 19,600 eV/particle 20,030 eV/particle 20,570 eV/particle 20,920.6 eV/particle 83,976.2 eV/particle 85,614.4 eV/particle

Heat of Vaporization	738 kJ/mol
Heat of Fusion	31.7 kJ/mol
Heat of Formation	787 kJ/mol
Electrons
Electron Shells	2, 8, 18, 32, 14, 2

Valence Electrons	2
Electron Configuration	[Xe] 4f¹⁴ 5d⁶ 6s²

Oxidation States	-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8
Electronegativity	9.78 eV/particle 0.2479845 2.2
Electrophilicity	1.5497236992588812 eV/particle
Phases
Phase	Solid
Gas Phase
Boiling Point	5,281.15 K
Melting Point	3,306.15 K
Critical Pressure
Critical Temperature
Triple Point
Visual
Osmium is a Slate Gray. Os has a CPK of #ff1493, Jmol of #266696, and MOLCAS GV of #266696. The Appearance of Element 76 is silvery, blue cast.
Color	Slate Gray #ff1493 #266696 #266696
Appearance	silvery, blue cast
Refractive Index
Thermodynamic Properties
Thermal Conductivity
Thermal Expansion	0.0000051 1/K
Molar Heat Capacity	24.7 J/(mol K)
Specific Heat Capacity	0.13 J/(g⋅K)
Heat Capacity Ratio (Adiabatic Index)
Electrical Properties
Type	Conductor
Electrical Conductivity	12 MS/m
Electrical Resistivity	0.00000008000000000001 m Ω
Superconducting Point	0.66 K
Magnetism
Type	paramagnetic
Magnetic Susceptibility (Mass)	0.0000000006 m³/Kg
Magnetic Susceptibility (Molar)	0.00000000011 m³/mol
Magnetic Susceptibility (Volume)	0.000014
Magnetic Ordering
Curie Point
Neel Point
Structure
The Crystal Structure of Osmium is HEX. The lattice constant of Os is 2.74 Å. The lattice angles of Element 76 are π/2, π/2, 2 π/3.
Crystal Structure	Simple Hexagonal (HEX)
Lattice Constant	2.74 Å
Lattice Angles	π/2, π/2, 2 π/3
Mechanical Properties
Osmium has a Brinell of 3920 MPa, and Mohs hardness of 7 MPa. The Shear Modulus of Os is 222 GPa. The Poisson Ratio of Element 76 is 0.25. The Speed of Sound of Osmium (Os) is 4940 m/s.
Hardness	3,920 MPa 7 MPa
Bulk Modulus
Shear Modulus	222 GPa
Young Modulus
Poisson Ratio	0.25
Speed of Sound	4,940 m/s
Classification
The CAS Group of Osmium is VIIIA. The IUPAC Group of Os is VIII. The Glawe Number of Element 76 is 60. The Mendeleev Number of Osmium (Os) is 61. The Pettifor Number of Osmium is 62. The Geochemical Class of Os is noble metal. The Goldschmidt Class of Element 76 is siderophile.
Category	Transition metals, Transition metals
CAS Group	VIIIA
IUPAC Group	VIII
Glawe Number	60
Mendeleev Number	61
Pettifor Number	62
Geochemical Class	noble metal
Goldschmidt Class	siderophile
Other
The Dipole Polarizability of Osmium is 57 plus or minus 3 a₀. Os has a C6 Dispersion Coefficient (GB) of 584 a₀. The Allotropes of Element 76 is . The Neutron Cross Section of Osmium (Os) is 15. The Neutron Mass Absorption of Osmium is 0.0023. The Quantum Numbers of Os is 5D4. The Space Group of Element 76 is 194 (P63/mmc).
Gas Basicity
Dipole Polarizability	57 ± 3 a₀
C6 Dispersion Coefficient	584 a₀
Allotropes
Neutron Cross Section	15
Neutron Mass Absorption	0.0023
Quantum Numbers	5D4
Space Group	194 (P63/mmc)

Isotopes of Osmium

Stable Isotopes	7
Unstable Isotopes	36
Radioactive Isotopes	38

¹⁶¹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	160.989054 ± 0.000429 Da
Mass Number	161
G-Factor
Half Life	640 ± 60 us
Spin	7/2
Quadrupole Moment
Discovery Year	2010
Parity	-

¹⁶¹Os Decay Modes

Decay Mode	Intensity
α (α emission)	100%

¹⁶²Os

Abundance	Radioactive ☢️
Relative Atomic Mass	161.984434 ± 0.000322 Da
Mass Number	162
G-Factor	0
Half Life	2.1 ± 0.1 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1989
Parity	+

¹⁶²Os Decay Modes

Decay Mode	Intensity
α (α emission)	100%

¹⁶³Os

Abundance	Radioactive ☢️
Relative Atomic Mass	162.982462 ± 0.000322 Da
Mass Number	163
G-Factor
Half Life	5.7 ± 0.5 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1981
Parity	-

¹⁶³Os Decay Modes

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

¹⁶⁴Os

Abundance	Radioactive ☢️
Relative Atomic Mass	163.978073158 ± 0.000160927 Da
Mass Number	164
G-Factor	0
Half Life	21 ± 1 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1981
Parity	+

¹⁶⁴Os Decay Modes

Decay Mode	Intensity
α (α emission)	96%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

¹⁶⁵Os

Abundance	Radioactive ☢️
Relative Atomic Mass	164.976654 ± 0.000215 Da
Mass Number	165
G-Factor
Half Life	71 ± 3 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1978
Parity	-

¹⁶⁵Os Decay Modes

Decay Mode	Intensity
α (α emission)	90%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	10%

¹⁶⁶Os

Abundance	Radioactive ☢️
Relative Atomic Mass	165.972698135 ± 0.000019287 Da
Mass Number	166
G-Factor	0
Half Life	213 ± 5 ms
Spin	0
Quadrupole Moment	0
Discovery Year	1977
Parity	+

¹⁶⁶Os Decay Modes

Decay Mode	Intensity
α (α emission)	83%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	17%

¹⁶⁷Os

Abundance	Radioactive ☢️
Relative Atomic Mass	166.971552304 ± 0.000086841 Da
Mass Number	167
G-Factor
Half Life	839 ± 5 ms
Spin	7/2
Quadrupole Moment
Discovery Year	1977
Parity	-

¹⁶⁷Os Decay Modes

Decay Mode	Intensity
α (α emission)	51%
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%

¹⁶⁸Os

Abundance	Radioactive ☢️
Relative Atomic Mass	167.96779905 ± 0.000010631 Da
Mass Number	168
G-Factor	0
Half Life	2.1 ± 0.1 s
Spin	0
Quadrupole Moment	0
Discovery Year	1977
Parity	+

¹⁶⁸Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	57%
α (α emission)	43%

¹⁶⁹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	168.967017521 ± 0.000027847 Da
Mass Number	169
G-Factor
Half Life	3.46 ± 0.11 s
Spin	5/2
Quadrupole Moment
Discovery Year	1972
Parity	-

¹⁶⁹Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	86.3%
α (α emission)	13.7%

¹⁷⁰Os

Abundance	Radioactive ☢️
Relative Atomic Mass	169.963579273 ± 0.000010476 Da
Mass Number	170
G-Factor	0
Half Life	7.37 ± 0.18 s
Spin	0
Quadrupole Moment	0
Discovery Year	1972
Parity	+

¹⁷⁰Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	90.5%
α (α emission)	9.5%

¹⁷¹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	170.963180402 ± 0.000019589 Da
Mass Number	171
G-Factor
Half Life	8.3 ± 0.2 s
Spin	5/2
Quadrupole Moment
Discovery Year	1972
Parity	-

¹⁷¹Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	%
α (α emission)	1.8%

¹⁷²Os

Abundance	Radioactive ☢️
Relative Atomic Mass	171.960017309 ± 0.000013704 Da
Mass Number	172
G-Factor	0
Half Life	19.2 ± 0.9 s
Spin	0
Quadrupole Moment	0
Discovery Year	1971
Parity	+

¹⁷²Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	98.81%
α (α emission)	1.19%

¹⁷³Os

Abundance	Radioactive ☢️
Relative Atomic Mass	172.959808387 ± 0.000016059 Da
Mass Number	173
G-Factor
Half Life	22.4 ± 0.9 s
Spin	5/2
Quadrupole Moment
Discovery Year	1971
Parity	-

¹⁷³Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	99.6%
α (α emission)	0.4%

¹⁷⁴Os

Abundance	Radioactive ☢️
Relative Atomic Mass	173.957063192 ± 0.000011008 Da
Mass Number	174
G-Factor	0
Half Life	44 ± 4 s
Spin	0
Quadrupole Moment	0
Discovery Year	1971
Parity	+

¹⁷⁴Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%
α (α emission)	0.024%

¹⁷⁵Os

Abundance	Radioactive ☢️
Relative Atomic Mass	174.956945126 ± 0.00001264 Da
Mass Number	175
G-Factor
Half Life	1.4 ± 0.1 m
Spin	5/2
Quadrupole Moment
Discovery Year	1972
Parity	-

¹⁷⁵Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁷⁶Os

Abundance	Radioactive ☢️
Relative Atomic Mass	175.954770315 ± 0.000011754 Da
Mass Number	176
G-Factor	0
Half Life	3.6 ± 0.5 m
Spin	0
Quadrupole Moment	0
Discovery Year	1970
Parity	+

¹⁷⁶Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁷⁷Os

Abundance	Radioactive ☢️
Relative Atomic Mass	176.954957902 ± 0.000015687 Da
Mass Number	177
G-Factor
Half Life	3 ± 0.2 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1970
Parity	-

¹⁷⁷Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁷⁸Os

Abundance	Radioactive ☢️
Relative Atomic Mass	177.953253334 ± 0.000014634 Da
Mass Number	178
G-Factor	0
Half Life	5 ± 0.4 m
Spin	0
Quadrupole Moment	0
Discovery Year	1967
Parity	+

¹⁷⁸Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁷⁹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	178.953815985 ± 0.000016645 Da
Mass Number	179
G-Factor
Half Life	6.5 ± 0.3 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1968
Parity	-

¹⁷⁹Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁰Os

Abundance	Radioactive ☢️
Relative Atomic Mass	179.952381665 ± 0.000016878 Da
Mass Number	180
G-Factor	0
Half Life	21.5 ± 0.4 m
Spin	0
Quadrupole Moment	0
Discovery Year	1967
Parity	+

¹⁸⁰Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸¹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	180.953247188 ± 0.000027201 Da
Mass Number	181
G-Factor
Half Life	105 ± 3 m
Spin	1/2
Quadrupole Moment	0
Discovery Year	1966
Parity	-

¹⁸¹Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸²Os

Abundance	Radioactive ☢️
Relative Atomic Mass	181.952110154 ± 0.000023344 Da
Mass Number	182
G-Factor	0
Half Life	21.84 ± 0.2 h
Spin	0
Quadrupole Moment	0
Discovery Year	1950
Parity	+

¹⁸²Os Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	100%

¹⁸³Os

Abundance	Radioactive ☢️
Relative Atomic Mass	182.953125028 ± 0.000053428 Da
Mass Number	183
G-Factor	0.17644444444444 ± 0.0031111111111111
Half Life	13 ± 0.5 h
Spin	9/2
Quadrupole Moment	3.1 ± 0.3
Discovery Year	1950
Parity	+

¹⁸³Os Decay Modes

Decay Mode	Intensity
β⁺ (β⁺ decay; β⁺ = ϵ + e⁺)	100%

¹⁸⁴Os

Abundance	Radioactive ☢️ 0.02 ± 0.02
Relative Atomic Mass	183.952492919 ± 0.00000089 Da
Mass Number	184
G-Factor	0
Half Life	11.2 ± 2.3 Ty
Spin	0
Quadrupole Moment	0
Discovery Year	1937
Parity	+

¹⁸⁴Os Decay Modes

Decay Mode	Intensity
α (α emission)	%
2β⁺ (double β⁺ decay)	%

¹⁸⁵Os

Abundance	Radioactive ☢️
Relative Atomic Mass	184.954045969 ± 0.000000893 Da
Mass Number	185
G-Factor
Half Life	92.95 ± 0.09 d
Spin	1/2
Quadrupole Moment	0
Discovery Year	1947
Parity	-

¹⁸⁵Os Decay Modes

Decay Mode	Intensity
ϵ (electron capture)	100%

¹⁸⁶Os

Abundance	Radioactive ☢️ 1.59 ± 0.64
Relative Atomic Mass	185.953837569 ± 0.000000816 Da
Mass Number	186
G-Factor	0
Half Life	2 ± 1.1 Py
Spin	0
Quadrupole Moment	0
Discovery Year	1931
Parity	+

¹⁸⁶Os Decay Modes

Decay Mode	Intensity
α (α emission)	100%

¹⁸⁷Os

Abundance	1.96 ± 0.17
Relative Atomic Mass	186.955749569 ± 0.000000791 Da
Mass Number	187
G-Factor
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year	1931
Parity	-

¹⁸⁷Os Decay Modes

Decay Mode	Intensity
α (α emission)	%

¹⁸⁸Os

Abundance	13.24 ± 0.27
Relative Atomic Mass	187.955837292 ± 0.000000788 Da
Mass Number	188
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1931
Parity	+

¹⁸⁸Os Decay Modes

Decay Mode	Intensity
α (α emission)	%

¹⁸⁹Os

Abundance	16.15 ± 0.23
Relative Atomic Mass	188.958145949 ± 0.000000715 Da
Mass Number	189
G-Factor
Half Life
Spin	3/2
Quadrupole Moment	0.86 ± 0.03
Discovery Year	1931
Parity	-

¹⁸⁹Os Decay Modes

Decay Mode	Intensity
α (α emission)	%

¹⁹⁰Os

Abundance	26.26 ± 0.2
Relative Atomic Mass	189.958445442 ± 0.000000697 Da
Mass Number	190
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1931
Parity	+

¹⁹⁰Os Decay Modes

Decay Mode	Intensity
α (α emission)	%

¹⁹¹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	190.960928105 ± 0.000000707 Da
Mass Number	191
G-Factor	0.21333333333333 ± 0.0066666666666667
Half Life	14.99 ± 0.02 d
Spin	9/2
Quadrupole Moment	2.53 ± 0.16
Discovery Year	1940
Parity	-

¹⁹¹Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹²Os

Abundance	40.78 ± 0.32
Relative Atomic Mass	191.961478765 ± 0.000002484 Da
Mass Number	192
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	1931
Parity	+

¹⁹²Os Decay Modes

Decay Mode	Intensity
2β⁻ (double β⁻ decay)	%
α (α emission)	%

¹⁹³Os

Abundance	Radioactive ☢️
Relative Atomic Mass	192.964149637 ± 0.00000249 Da
Mass Number	193
G-Factor	0.48666666666667 ± 0.0013333333333333
Half Life	29.83 ± 0.018 h
Spin	3/2
Quadrupole Moment
Discovery Year	1940
Parity	-

¹⁹³Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁴Os

Abundance	Radioactive ☢️
Relative Atomic Mass	193.965179407 ± 0.000002579 Da
Mass Number	194
G-Factor	0
Half Life	6 ± 0.2 y
Spin	0
Quadrupole Moment	0
Discovery Year	1951
Parity	+

¹⁹⁴Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁵Os

Abundance	Radioactive ☢️
Relative Atomic Mass	194.968318 ± 0.00006 Da
Mass Number	195
G-Factor
Half Life	6.5 ± 1.1 m
Spin	3/2
Quadrupole Moment
Discovery Year	2004
Parity	-

¹⁹⁵Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁶Os

Abundance	Radioactive ☢️
Relative Atomic Mass	195.969643261 ± 0.000043 Da
Mass Number	196
G-Factor	0
Half Life	34.9 ± 0.2 m
Spin	0
Quadrupole Moment	0
Discovery Year	1977
Parity	+

¹⁹⁶Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁷Os

Abundance	Radioactive ☢️
Relative Atomic Mass	196.973076 ± 0.000215 Da
Mass Number	197
G-Factor
Half Life	93 ± 7 s
Spin	5/2
Quadrupole Moment
Discovery Year	2003
Parity	-

¹⁹⁷Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁸Os

Abundance	Radioactive ☢️
Relative Atomic Mass	197.974664 ± 0.000215 Da
Mass Number	198
G-Factor	0
Half Life	125 ± 28 s
Spin	0
Quadrupole Moment	0
Discovery Year	2008
Parity	+

¹⁹⁸Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

¹⁹⁹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	198.978239 ± 0.000215 Da
Mass Number	199
G-Factor
Half Life	6 ± 3 s
Spin	5/2
Quadrupole Moment
Discovery Year	2008
Parity	-

¹⁹⁹Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁰⁰Os

Abundance	Radioactive ☢️
Relative Atomic Mass	199.980086 ± 0.000322 Da
Mass Number	200
G-Factor	0
Half Life	7 ± 4 s
Spin	0
Quadrupole Moment	0
Discovery Year	2005
Parity	+

²⁰⁰Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	100%

²⁰¹Os

Abundance	Radioactive ☢️
Relative Atomic Mass	200.984069 ± 0.000322 Da
Mass Number	201
G-Factor
Half Life
Spin	1/2
Quadrupole Moment	0
Discovery Year	2009
Parity	-

²⁰¹Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

²⁰²Os

Abundance	Radioactive ☢️
Relative Atomic Mass	201.986548 ± 0.000429 Da
Mass Number	202
G-Factor	0
Half Life
Spin	0
Quadrupole Moment	0
Discovery Year	2009
Parity	+

²⁰²Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%

²⁰³Os

Abundance	Radioactive ☢️
Relative Atomic Mass	202.992195 ± 0.000429 Da
Mass Number	203
G-Factor
Half Life
Spin	9/2
Quadrupole Moment
Discovery Year	2012
Parity	+

²⁰³Os Decay Modes

Decay Mode	Intensity
β⁻ (β⁻ decay)	%
β⁻ n (β⁻-delayed neutron emission)	%

History

Osmium was discovered in 1803 by English chemist Smithson Tennant in London. Chemists who studied platinum dissolved it in aqua regia to create soluble salts and observed a small amount of a dark, insoluble residue. Smithson Tennant analyzed the insoluble residue and concluded that it must contain a new metal. From the Greek word osme, meaning smell

Discoverers	Smithson Tenant
Discovery Location	England
Discovery Year	1804
Etymology (Name Origin)	Greek: osmê (odor).
Pronunciation	OZ-mi-em (English)

Even low concentrations in air can cause lung congestion, skin damage, or eye damage

Osmium is the least abundant stable element in the Earth's crust

Uses

Osmium is used alloyed with other metals in the platinum group to produce very hard alloys. Osmium alloys are used in the tips of fountain pens, instrument pivots, and electrical contacts Osmium tetroxide has been used in fingerprint detection and in staining fatty tissue for optical and electron microscopy. Used to tip gold pen points, instrument pivots, to make electric light filaments. Used for high temp. alloys and pressure bearings. Very hard and resists corrosion better than any other.

Sources

Obtained from the same ores as platinum.

Abundance
Abundance in Earth's crust	0.0015 mg/kg
Abundance in Oceans
Abundance in Human Body
Abundance in Meteor	0.000066 %
Abundance in Sun	0.0000002 %
Abundance in Universe	0.0000003 %

Nuclear Screening Constants

1	s	1.4701
2	p	4.4502
2	s	19.8502
3	d	13.5253
3	p	21.7483
3	s	22.5727
4	d	37.142
4	f	38.8472
4	p	34.856
4	s	33.9048
5	d	58.003
5	p	53.09
5	s	50.905
6	s	65.677

Osmium on ChemicalAid

Australian Educational Vocabulary ID	scot/3552
Brockhaus Enzyklopädie online ID	osmium
CAS Registry Number	7440-04-2
CPV Supplementary	AA41
ChEBI ID	30687
ChemSpider ID	22379
Common Procurement Vocabulary	14792000
DSSTOX compound identifier	DTXCID7047643
DSSTox substance ID	DTXSID5064679
De Agostini ID	òsmio
Den Store Danske ID	osmium
ECHA Substance Infocard ID	100.028.285
Encyclopædia Britannica Online ID	science/osmium
Encyclopædia Universalis ID	osmium
Freebase ID	/m/025s6b_
French Vikidia ID	Osmium
GND ID	4172906-7
Gran Enciclopèdia Catalana ID	0128455
Great Russian Encyclopedia Online ID	2680588
HSDB ID	7329
InChI	InChI=1S/Os
InChIKey	SYQBFIAQOQZEGI-UHFFFAOYSA-N
KBpedia ID	Osmium
Library of Congress authority ID	sh85095926
MeSH descriptor ID	D009992
NDL Authority ID	00568958
Namuwiki ID	오스뮴
National Library of Israel ID (old)	000724669
National Library of Israel J9U ID	987007553481505171
OmegaWiki Defined Meaning	340604
OpenAlex ID	C540285154
PSH ID	5777
PubChem CID	23937
RxNorm ID	1311130
Spanish Vikidia ID	Osmio
Store norske leksikon ID	osmium
Treccani ID	osmio
UM-BBD compound ID	c0926
UNII	2E7M255OPY
USGS Thesaurus ID	1530
Wolfram Language entity code	Entity["Mineral", "Osmium"]
WordNet 3.1 Synset ID	14672085-n
ZVG number	7760

Osmium (Os)

Properties

Isotopes of Osmium

161Os

161Os Decay Modes

162Os

162Os Decay Modes

163Os

163Os Decay Modes

164Os

164Os Decay Modes

165Os

165Os Decay Modes

166Os

166Os Decay Modes

167Os

167Os Decay Modes

168Os

168Os Decay Modes

169Os

169Os Decay Modes

170Os

170Os Decay Modes

171Os

171Os Decay Modes

172Os

172Os Decay Modes

173Os

173Os Decay Modes

174Os

174Os Decay Modes

175Os

175Os Decay Modes

176Os

176Os Decay Modes

177Os

177Os Decay Modes

178Os

178Os Decay Modes

179Os

179Os Decay Modes

180Os

180Os Decay Modes

181Os

181Os Decay Modes

182Os

182Os Decay Modes

183Os

183Os Decay Modes

184Os

184Os Decay Modes

185Os

185Os Decay Modes

186Os

186Os Decay Modes

187Os

187Os Decay Modes

188Os

188Os Decay Modes

189Os

189Os Decay Modes

190Os

190Os Decay Modes

191Os

191Os Decay Modes

192Os

192Os Decay Modes

193Os

193Os Decay Modes

194Os

194Os Decay Modes

195Os

195Os Decay Modes

196Os

196Os Decay Modes

197Os

197Os Decay Modes

198Os

198Os Decay Modes

199Os