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Os Osmium
Element Information, Facts, Properties, Trends, Uses, Comparison with other elements

76
Os
Osmium
Element 76 of Periodic table is Osmium with atomic number 76, atomic weight 190.23. Osmium, symbol Os, has a Simple Hexagonal structure and SlateGray color. Osmium is a Transition Metal element. It is part of group 8 (iron family). Know everything about Osmium Facts, Physical Properties, Chemical Properties, Electronic configuration, Atomic and Crystal Structure.
76 Os - Osmium | SchoolMyKids

Osmium (from Greek osme (ὀσμή) meaning 'smell') is a chemical element with symbol Os and atomic number 76. It is a hard, brittle, bluish-white Transition Metal in the platinum group that is found as a trace element in alloys, mostly in platinum ores. Osmium is the densest naturally occurring element, with a density of 7004225900000000000♠22.59 g/cm3.

It belongs to group 8 of the periodic table having trivial name .

Osmium Facts

Read key information and facts about element Osmium

NameOsmium
Atomic Number76
Atomic SymbolOs
Atomic Weight190.23
PhaseSolid
ColorSlateGray
Appearancesilvery, blue cast
ClassificationTransition Metal
Group in Periodic Table8
Group Nameiron family
Period in Periodic Tableperiod 6
Block in Periodic Tabled -block
Electronic Configuration[Xe] 4f14 5d6 6s2
Electronic Shell Structure (Electrons per shell)2, 8, 18, 32, 14, 2
Melting Point3306 K
Boiling Point5285 K
CAS NumberCAS7440-04-2
123456789101112131415161718
1
1
H
Hydrogen
1.008

Atomic #

Electronic Shell #

Symbol
Name
Atomic Weight
HGas
HgLiquid
CSolid
Metals
Metalloids
NonMetals
Alkali metals
Alkali earth metals
Lanthanoids
Transition metals
Post-transition metals
Other nonmetals
Halogens
Nobel gas
Actinoids
2
He
Helium
4.003
2
3
Li
Lithium
6.941
4
Be
Beryllium
9.012
5
B
Boron
10.811
6
C
Carbon
12.011
7
N
Nitrogen
14.007
8
O
Oxygen
15.999
9
F
Fluorine
18.998
10
Ne
Neon
20.180
3
11
Na
Sodium
22.990
12
Mg
Magnesium
24.305
13
Al
Aluminium
26.982
14
Si
Silicon
28.085
15
P
Phosphorus
30.974
16
S
Sulfur
32.065
17
Cl
Chlorine
35.453
18
Ar
Argon
39.948
4
19
K
Potassium
39.098
20
Ca
Calcium
40.078
21
Sc
Scandium
44.956
22
Ti
Titanium
47.867
23
V
Vanadium
50.941
24
Cr
Chromium
51.996
25
Mn
Manganese
54.938
26
Fe
Iron
55.845
27
Co
Cobalt
58.933
28
Ni
Nickel
58.693
29
Cu
Copper
63.546
30
Zn
Zinc
65.409
31
Ga
Gallium
69.723
32
Ge
Germanium
72.640
33
As
Arsenic
74.922
34
Se
Selenium
78.960
35
Br
Bromine
79.904
36
Kr
Krypton
83.798
5
37
Rb
Rubidium
85.468
38
Sr
Strontium
87.620
39
Y
Yttrium
88.906
40
Zr
Zirconium
91.224
41
Nb
Niobium
92.906
42
Mo
Molybdenum
95.940
43
Tc
Technetium
98
44
Ru
Ruthenium
101.070
45
Rh
Rhodium
102.906
46
Pd
Palladium
106.420
47
Ag
Silver
107.868
48
Cd
Cadmium
112.411
49
In
Indium
114.818
50
Sn
Tin
118.710
51
Sb
Antimony
121.760
52
Te
Tellurium
127.600
53
I
Iodine
126.904
54
Xe
Xenon
131.293
6
55
Cs
Cesium
132.905
56
Ba
Barium
137.327
57 - 71
La - Lu
Lanthanides
72
Hf
Hafnium
178.490
73
Ta
Tantalum
180.948
74
W
Tungsten
183.840
75
Re
Rhenium
186.207
76
Os
Osmium
190.230
77
Ir
Iridium
192.217
78
Pt
Platinum
195.078
79
Au
Gold
196.967
80
Hg
Mercury
200.590
81
Tl
Thallium
204.383
82
Pb
Lead
207.200
83
Bi
Bismuth
208.980
84
Po
Polonium
209
85
At
Astatine
210
86
Rn
Radon
222
7
87
Fr
Francium
223
88
Ra
Radium
226
89 - 103
Ac - Lr
Actinides
104
Rf
Rutherfordium
261
105
Db
Dubnium
262
106
Sg
Seaborgium
266
107
Bh
Bohrium
264
108
Hs
Hassium
277
109
Mt
Meitnerium
268
110
Ds
Darmstadtium
281
111
Rg
Roentgenium
272
112
Cn
Copernicium
285
113
Nh
Nihonium
284
114
Fl
Flerovium
289
115
Mc
Moscovium
288
116
Lv
Livermorium
292
117
Ts
Tennessine
294
118
Og
Oganesson
294
Lanthanides
57
La
Lanthanum
138.905
58
Ce
Cerium
140.116
59
Pr
Praseodymium
140.908
60
Nd
Neodymium
144.240
61
Pm
Promethium
145
62
Sm
Samarium
150.360
63
Eu
Europium
151.964
64
Gd
Gadolinium
157.250
65
Tb
Terbium
158.925
66
Dy
Dysprosium
162.500
67
Ho
Holmium
164.930
68
Er
Erbium
167.259
69
Tm
Thulium
168.934
70
Yb
Ytterbium
173.040
71
Lu
Lutetium
174.967
Actinides
89
Ac
Actinium
227
90
Th
Thorium
232.038
91
Pa
Protactinium
231.036
92
U
Uranium
238.029
93
Np
Neptunium
237
94
Pu
Plutonium
244
95
Am
Americium
243
96
Cm
Curium
247
97
Bk
Berkelium
247
98
Cf
Californium
251
99
Es
Einsteinium
252
100
Fm
Fermium
257
101
Md
Mendelevium
258
102
No
Nobelium
259
103
Lr
Lawrencium
262

How to Locate Osmium on Periodic Table

Periodic table is arranged by atomic number, number of protons in the nucleus which is same as number of electrons. The atomic number increases from left to right. Periodic table starts at top left ( Atomic number 1) and ends at bottom right (atomic number 118). Therefore you can directly look for atomic number 76 to find Osmium on periodic table.

Another way to read periodic table and locate an element is by using group number (column) and period number (row). To locate Osmium on periodic table look for cross section of group 8 and period 6 in the modern periodic table.

Osmium History

The element Osmium was discovered by S. Tennant in year 1803 in United Kingdom. Osmium was first isolated by S. Tennant in 1803. Osmium derived its name from the Greek osmè, meaning 'smell'.

Tennant had been working on samples of South American platinum in parallel with Wollaston and discovered two new elements, which he named osmium and iridium.

Osmium Presence: Abundance in Nature and Around Us

The table below shows the abundance of Osmium in Universe, Sun, Meteorites, Earth's Crust, Oceans and Human Body.

 ppb by weight (1ppb =10^-7 %)ppb by atoms (1ppb =10^-7 %)
Abundance in Universe30.02
Abundance in Sun20.02
Abundance in Meteorites67070
Abundance in Earth's Crust1.80.2
Abundance in Oceans--
Abundance in Humans--

Crystal Structure of Osmium

The solid state structure of Osmium is Simple Hexagonal.

The Crystal structure can be described in terms of its unit Cell. The unit Cells repeats itself in three dimensional space to form the structure.

Unit Cell Parameters

The unit cell is represented in terms of its lattice parameters, which are the lengths of the cell edges Lattice Constants (a, b and c)

abc
273.44 pm273.44 pm431.73 pm

and the angles between them Lattice Angles (alpha, beta and gamma).

alphabetagamma
π/2 π/2 2 π/3

The positions of the atoms inside the unit cell are described by the set of atomic positions ( xi, yi, zi) measured from a reference lattice point.

The symmetry properties of the crystal are described by the concept of space groups. All possible symmetric arrangements of particles in three-dimensional space are described by the 230 space groups (219 distinct types, or 230 if chiral copies are considered distinct.

Space Group NameP63/mmc 76 Os Osmium - Crystal Structure | SchoolMyKids
Oxidation StatesSpace Group Number194
Crystal StructureSimple Hexagonal

Osmium Atomic and Orbital Properties

Osmium atoms have 76 electrons and the electronic shell structure is [2, 8, 18, 32, 14, 2] with Atomic Term Symbol (Quantum Numbers) 5D4.

Atomic Number76
Number of Electrons (with no charge)76
Number of Protons76
Mass Number190
Number of Neutrons114
Shell structure (Electrons per energy level)2, 8, 18, 32, 14, 2
Electron Configuration[Xe] 4f14 5d6 6s2
Valence Electrons5d6 6s2
Valence (Valency)6
Main Oxidation States4
Oxidation States-4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8
Atomic Term Symbol (Quantum Numbers)5D4

Bohr Atomic Model of Osmium - Electrons per energy level

76 Os Osmium - Electron Shell Structure | SchoolMyKids
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Ground State Electronic Configuration of Osmium - neutral Osmium atom

Abbreviated electronic configuration of Osmium

The ground state abbreviated electronic configuration of Neutral Osmium atom is [Xe] 4f14 5d6 6s2. The portion of Osmium configuration that is equivalent to the noble gas of the preceding period, is abbreviated as [Xe]. For atoms with many electrons, this notation can become lengthy and so an abbreviated notation is used. This is important as it is the Valence electrons 5d6 6s2, electrons in the outermost shell that determine the chemical properties of the element.

Unabbreviated electronic configuration of neutral Osmium

Complete ground state electronic configuration for the Osmium atom, Unabbreviated electronic configuration

1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 5s2 5p6 4f14 5d6 6s2

Electrons are filled in atomic orbitals as per the order determined by the Aufbau principle, Pauli Exclusion Principle and Hund’s Rule.

  • As per the Aufbau principle the electrons will occupy the orbitals having lower energies before occupying higher energy orbitals. According to this principle, electrons are filled in the following order: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p…
  • The Pauli exclusion principle states that a maximum of two electrons, each having opposite spins, can fit in an orbital.
  • Hund's rule states that every orbital in a given subshell is singly occupied by electrons before a second electron is filled in an orbital.
  • Electron configuration of Osmium
    Atomic Structure of Osmium

    Osmium atomic radius is 185 pm, while it's covalent radius is 128 pm.

    Atomic Radius Calculated

    185 pm (1.85 Å)

    Atomic Radius Empirical

    130 pm (1.3 Å)

    Atomic Volume8.421 cm3/mol
    Covalent Radius128 pm (1.28 Å)
    Van der Waals Radius-
    Neutron Cross Section15
    Neutron Mass Absorption 0.0023

    Atomic Spectrum of Osmium

    Atomic Spectrum of Osmium | SchoolMyKids

    Osmium Chemical Properties: Osmium Ionization Energies and electron affinity

    The electron affinity of Osmium is 106.1 kJ/mol.

    Valence6
    Electronegativity2.2
    ElectronAffinity106.1 kJ/mol

    Ionization Energy of Osmium

    Refer to table below for Ionization energies of Osmium

    Ionization energy numberEnthalpy - kJ/mol
    1st840
    2nd1600

    Osmium Physical Properties

    Refer to below table for Osmium Physical Properties

    Density22.59 g/cm3(when liquid at m.p density is $20 g/cm3)
    Molar Volume8.421 cm3/mol

    Elastic Properties

    Young Modulus-
    Shear Modulus222 GPa
    Bulk Modulus -
    Poisson Ratio0.25

    Hardness of Osmium - Tests to Measure of Hardness of Element

    Mohs Hardness7 MPa
    Vickers Hardness-
    Brinell Hardness3920 MPa

    Osmium Electrical Properties

    Osmium is Conductor of electricity. Refer to table below for the Electrical properties ofOsmium

    Electrical Conductivity12000000 S/m
    Resistivity8.1e-8 m Ω
    Superconducting Point0.66

    Osmium Heat and Conduction Properties

    Thermal Conductivity88 W/(m K)
    Thermal Expansion0.0000051 /K

    Osmium Magnetic Properties

    Magnetic TypeParamagnetic
    Curie Point-
    Mass Magnetic Susceptibility6e-10 m3/kg
    Molar Magnetic Susceptibility1.1e-10 m3/mol
    Volume Magnetic Susceptibility0.000014

    Optical Properties of Osmium

    Refractive Index-

    Acoustic Properties of Osmium

    Speed of Sound4940 m/s

    Osmium Thermal Properties - Enthalpies and thermodynamics

    Refer to table below for Thermal properties of Osmium

    Melting Point3306 K (3032.85°C, 5491.129999999999 °F)
    Boiling Point5285 K (5011.85°C, 9053.33 °F)
    Critical Temperature-
    Superconducting Point0.66

    Enthalpies of Osmium

    Heat of Fusion31 kJ/mol
    Heat of Vaporization630 kJ/mol
    Heat of Combustion-

    Osmium Isotopes - Nuclear Properties of Osmium

    Osmium has 35 isotopes, with between 162 and 196 nucleons. Osmium has 6 stable naturally occuring isotopes.

    Isotopes of Osmium - Naturally occurring stable Isotopes: 184Os, 187Os, 188Os, 189Os, 190Os, 192Os.

    IsotopeZNIsotope Mass% AbundanceT halfDecay Mode
    162Os7686162Synthetic
    163Os7687163Synthetic
    164Os7688164Synthetic
    165Os7689165Synthetic
    166Os7690166Synthetic
    167Os7691167Synthetic
    168Os7692168Synthetic
    169Os7693169Synthetic
    170Os7694170Synthetic
    171Os7695171Synthetic
    172Os7696172Synthetic
    173Os7697173Synthetic
    174Os7698174Synthetic
    175Os7699175Synthetic
    176Os76100176Synthetic
    177Os76101177Synthetic
    178Os76102178Synthetic
    179Os76103179Synthetic
    180Os76104180Synthetic
    181Os76105181Synthetic
    182Os76106182Synthetic
    183Os76107183Synthetic
    184Os761081840.02%StableN/A
    185Os76109185Synthetic
    186Os761101861.59%StableN/A
    187Os761111871.96%StableN/A
    188Os7611218813.24%StableN/A
    189Os7611318916.15%StableN/A
    190Os7611419026.26%Stable
    191Os76115191Synthetic
    192Os7611619240.78%StableN/A
    193Os76117193Synthetic
    194Os76118194Synthetic
    195Os76119195Synthetic
    196Os76120196Synthetic

    Regulatory and Health - Health and Safety Parameters and Guidelines

    Database Search

    List of unique identifiers to search the element in various chemical registry databases

    DatabaseIdentifier number
    CAS Number - Chemical Abstracts Service (CAS)CAS7440-04-2
    RTECS NumberRTECSRN1100000
    CID Number CID23937
    Gmelin Number-
    NSC Number-