Symbol
Bh
Cr
Group Number
76
0
17
👆🏻
Period Number
74
2
7
👆🏻
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
540371487440473
7429905
54386242
👆🏻
Space Group Name
-
Im_ 3m
Space Group Number
276.00229.00
11
276
👆🏻
Interesting Facts
- Bohrium metal is also known as Unnilseptium (Uns) and Nielsbohrium (Ns).
- Chromium is highly reactive, hence it is not found free in nature.
- Ores of Chromites mineral are the major source of Chromium metal.
- Almost 90% leather tanning is done with the help of chromium.
Sources
Found in Minerals, Mining, Synthetically Produced
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
Gesellschaft für Schwerionenforschung
Louis Nicolas Vauquelin
Discovery
In 1981
In Between 1797 - 1798
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
-0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %0.30 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.01 %
1E-37
8.1
👆🏻
Abundance In Oceans
-0.00 %
0
1.1
👆🏻
Abundance In Humans
-0.00 %
0
1.4
👆🏻
Uses & Benefits
- Currently known uses of Bohrium metal are limited to research purpose only.
- It is used to harden the steel and produces a stainless steel and other various alloys.
- It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
Industrial Uses
-
Automobile Industry, Chemical Industry
Medical Uses
-
-
Other Uses
Research Purposes
Alloys
Biological Properties
Toxicity
-
Highly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.11 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.33 p.p.m.
0
170000
👆🏻
Melting Point
-1,857.00 °C
-38.83
3410
👆🏻
Boiling Point
0.00 °C2,672.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
-
Silver
Luster
Unknown Luster
Metallic
Hardness
Mohs Hardness
7.008.50
0.2
8.5
👆🏻
Brinell Hardness
270.00 MPa687.00 MPa
0.14
3490
👆🏻
Vickers Hardness
2,700.00 MPa1,060.00 MPa
0
3920
👆🏻
Speed of Sound
2,680.00 m/s5,940.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.502.97
0.155
3.41
👆🏻
Reflectivity
59.00 %70.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Bh
Cr
Isotopes
Known Isotopes
521
0
38
👆🏻
Electronegativity
Pauling Electronegativity
2.001.66
0
2.6
👆🏻
Sanderson Electronegativity
1.301.66
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.301.56
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.301.66
0.62
2.48
👆🏻
Allen Electronegativity
2.001.65
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.002.34
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
742.90 kJ/mol26,130.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,688.50 kJ/mol28,750.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,566.50 kJ/mol34,230.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,598.90 kJ/mol37,066.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
4,727.80 kJ/mol97,510.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,991.70 kJ/mol105,800.00 kJ/mol
1007
105800
👆🏻
7th Energy level
7,226.80 kJ/mol114,300.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
7,100.00 kJ/mol125,300.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,800.00 kJ/mol134,700.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
7,100.00 kJ/mol144,300.00 kJ/mol
392
144300
👆🏻
11th Energy Level
8,200.00 kJ/mol26,130.00 kJ/mol
392
169988
👆🏻
12th Energy Level
82,700.00 kJ/mol28,750.00 kJ/mol
0
189368
👆🏻
13th Energy Level
7,100.00 kJ/mol34,230.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
8,200.00 kJ/mol37,066.00 kJ/mol
380
86450
👆🏻
15th Energy Level
82,000.00 kJ/mol97,510.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
71,100.00 kJ/mol105,800.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
820.00 kJ/mol114,300.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
8,200.00 kJ/mol125,300.00 kJ/mol
0
134810
👆🏻
19th Energy Level
820.80 kJ/mol134,700.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
820.00 kJ/mol144,300.00 kJ/mol
0
171200
👆🏻
21st Energy Level
8,200.00 kJ/mol157,700.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
820.00 kJ/mol166,090.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
8,200.00 kJ/mol653.80 kJ/mol
357.6
198800
👆🏻
24th Energy Level
820.00 kJ/mol653.80 kJ/mol
297.3
195200
👆🏻
25th Energy Level
820.00 kJ/mol653.80 kJ/mol
0
121900
👆🏻
26th Energy Level
820.00 kJ/mol653.80 kJ/mol
357.6
127700
👆🏻
27th Energy Level
820.00 kJ/mol652.90 kJ/mol
0
133800
👆🏻
28th Energy Level
820.00 kJ/mol653.80 kJ/mol
297.3
139800
👆🏻
29th Energy Level
820.00 kJ/mol653.80 kJ/mol
0
148100
👆🏻
30th Energy Level
820.00 kJ/mol653.80 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
3.00 g/amp-hr0.32 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.90 eV4.50 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Number
10724
3
117
👆🏻
Electron Configuration
[Rn] 5f14 6d5 7s2
[Ar] 3d5 4s1
Crystal Structure
Hexagonal Close Packed (HCP)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
10724
3
117
👆🏻
Number of Neutrons
15528
4
285
👆🏻
Number of Electrons
10724
3
117
👆🏻
Radius of an Atom
Atomic Radius
128.00 pm128.00 pm
0
348
👆🏻
Covalent Radius
141.00 pm139.00 pm
0
260
👆🏻
Van der Waals Radius
0.00 pm200.00 pm
0
348
👆🏻
Atomic Weight
270.00 amu52.00 amu
6.94
294
👆🏻
Atomic Volume
23.70 cm3/mol7.23 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
27.20 (-eV)170.00 (-eV)
0
392.42
👆🏻
Lattice Constant
-291.00 pm
0
891.25
👆🏻
Lattice Angles
-
π/2, π/2, π/2
Lattice C/A Ratio
1.571.86
0.423
1.9
👆🏻
Density
Density At Room Temperature
37.10 g/cm37.19 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
37.10 g/cm36.30 g/cm3
0.512
41
👆🏻
Tensile Strength
152.00 MPa689.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)774.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
28.00 GPa115.00 GPa
1.3
222
👆🏻
Bulk Modulus
37.00 GPa160.00 GPa
0
462
👆🏻
Young's Modulus
0.00 GPa279.00 GPa
0
528
👆🏻
Poisson Ratio
0.350.21
0.032
0.47
👆🏻
Other Mechanical Properties
-
-
Magnetic Characteristics
Specific Gravity
37.007.19
0.53
4500
👆🏻
Magnetic Ordering
-
Antiferromagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
-
-
Resistivity
6.50 nΩ·m125.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.00 106/cm Ω0.08 106/cm Ω
0
0.63
👆🏻
Electron Affinity
-64.30 kJ/mol
0
222.8
👆🏻
Specific Heat
0.10 J/(kg K)0.45 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
37.10 J/mol·K23.35 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
37.00 W/m·K93.90 W/m·K
0
429
👆🏻
Critical Temperature
1,323.00 K1,907.00 K
26.3
3695
👆🏻
Thermal Expansion
14.30 µm/(m·K)4.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
270.50 kJ/mol348.80 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
-15.31 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
-397.50 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
57.00 J/mol.K23.80 J/mol.K
9.5
198.1
👆🏻