Symbol
Rh
Cr
Group Number
96
0
17
👆🏻
Period Number
54
2
7
👆🏻
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
74401667440473
7429905
54386242
👆🏻
Space Group Name
Fm_ 3m
Im_ 3m
Space Group Number
225.00229.00
11
276
👆🏻
Interesting Facts
- Rhodium is the rarest element out of all non-radioactive metals on the earth .
- Rhodium is one of the most durable and hard metal, which also have high reflectance.
- 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
Earth's crust, Found As a By-product, Found in Minerals, Mining
Found in Minerals, Mining, Ores of metals, Ores of Minerals
History
Who Discovered
William Hyde Wollaston
Louis Nicolas Vauquelin
Discovery
In 1804
In Between 1797 - 1798
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %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 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Rhodium metal is mainly used in catalytic converters for cars as it reduces nitrogen oxides in exhaust gases.
- It is used as an industrial catalyst for nitric acid, acetic acid, hydrogenation reaction, etc.
- 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
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Automobile Industry, Chemical Industry
Medical Uses
-
-
Other Uses
Alloys
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
1,966.00 °C1,857.00 °C
-38.83
3410
👆🏻
Boiling Point
3,727.00 °C2,672.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silver
Luster
Metallic
Metallic
Hardness
Mohs Hardness
6.008.50
0.2
8.5
👆🏻
Brinell Hardness
980.00 MPa687.00 MPa
0.14
3490
👆🏻
Vickers Hardness
1,100.00 MPa1,060.00 MPa
0
3920
👆🏻
Speed of Sound
4,700.00 m/s5,940.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.402.97
0.155
3.41
👆🏻
Reflectivity
84.00 %70.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Rh
Cr
Isotopes
Known Isotopes
1621
0
38
👆🏻
Electronegativity
Pauling Electronegativity
2.281.66
0
2.6
👆🏻
Sanderson Electronegativity
2.281.66
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.451.56
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
2.281.66
0.62
2.48
👆🏻
Allen Electronegativity
1.561.65
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
1.722.34
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
719.70 kJ/mol26,130.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,740.00 kJ/mol28,750.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,997.00 kJ/mol34,230.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
7,197.00 kJ/mol37,066.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
7,197.00 kJ/mol97,510.00 kJ/mol
392
97510
👆🏻
6th Energy Level
7,197.00 kJ/mol105,800.00 kJ/mol
1007
105800
👆🏻
7th Energy level
7,197.00 kJ/mol114,300.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
3,480.00 kJ/mol125,300.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,090.00 kJ/mol134,700.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
7,197.00 kJ/mol144,300.00 kJ/mol
392
144300
👆🏻
11th Energy Level
7,197.00 kJ/mol26,130.00 kJ/mol
392
169988
👆🏻
12th Energy Level
7,190.00 kJ/mol28,750.00 kJ/mol
0
189368
👆🏻
13th Energy Level
7,190.00 kJ/mol34,230.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
7,197.00 kJ/mol37,066.00 kJ/mol
380
86450
👆🏻
15th Energy Level
71,900.00 kJ/mol97,510.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
71,900.00 kJ/mol105,800.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
719.70 kJ/mol114,300.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
7,197.00 kJ/mol125,300.00 kJ/mol
0
134810
👆🏻
19th Energy Level
719.70 kJ/mol134,700.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
719.00 kJ/mol144,300.00 kJ/mol
0
171200
👆🏻
21st Energy Level
719.70 kJ/mol157,700.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
719.00 kJ/mol166,090.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
719.70 kJ/mol653.80 kJ/mol
357.6
198800
👆🏻
24th Energy Level
719.70 kJ/mol653.80 kJ/mol
297.3
195200
👆🏻
25th Energy Level
719.00 kJ/mol653.80 kJ/mol
0
121900
👆🏻
26th Energy Level
719.70 kJ/mol653.80 kJ/mol
357.6
127700
👆🏻
27th Energy Level
719.70 kJ/mol652.90 kJ/mol
0
133800
👆🏻
28th Energy Level
719.70 kJ/mol653.80 kJ/mol
297.3
139800
👆🏻
29th Energy Level
719.70 kJ/mol653.80 kJ/mol
0
148100
👆🏻
30th Energy Level
719.00 kJ/mol653.80 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.28 g/amp-hr0.32 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.98 eV4.50 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility
Atomic Number
4524
3
117
👆🏻
Electron Configuration
[Kr] 4d8 5s1
[Ar] 3d5 4s1
Crystal Structure
Face Centered Cubic (FCC)
Body Centered Cubic (BCC)
Crystal Lattice
Atom
Number of Protons
4524
3
117
👆🏻
Number of Neutrons
5828
4
285
👆🏻
Number of Electrons
4524
3
117
👆🏻
Radius of an Atom
Atomic Radius
134.00 pm128.00 pm
0
348
👆🏻
Covalent Radius
142.00 pm139.00 pm
0
260
👆🏻
Van der Waals Radius
200.00 pm200.00 pm
0
348
👆🏻
Atomic Weight
102.91 amu52.00 amu
6.94
294
👆🏻
Atomic Volume
8.30 cm3/mol7.23 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
64.00 (-eV)170.00 (-eV)
0
392.42
👆🏻
Lattice Constant
380.34 pm291.00 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
1.731.86
0.423
1.9
👆🏻
Density
Density At Room Temperature
12.41 g/cm37.19 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
10.70 g/cm36.30 g/cm3
0.512
41
👆🏻
Tensile Strength
951.00 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
0.02 (Pa)774.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
150.00 GPa115.00 GPa
1.3
222
👆🏻
Bulk Modulus
275.00 GPa160.00 GPa
0
462
👆🏻
Young's Modulus
380.00 GPa279.00 GPa
0
528
👆🏻
Poisson Ratio
0.260.21
0.032
0.47
👆🏻
Other Mechanical Properties
Malleable
-
Magnetic Characteristics
Specific Gravity
12.417.19
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
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
Conductor
-
Resistivity
43.30 nΩ·m125.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.21 106/cm Ω0.08 106/cm Ω
0
0.63
👆🏻
Electron Affinity
109.70 kJ/mol64.30 kJ/mol
0
222.8
👆🏻
Specific Heat
0.24 J/(kg K)0.45 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
24.98 J/mol·K23.35 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
150.00 W/m·K93.90 W/m·K
0
429
👆🏻
Critical Temperature
2,237.00 K1,907.00 K
26.3
3695
👆🏻
Thermal Expansion
8.20 µm/(m·K)4.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
495.40 kJ/mol348.80 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
21.76 kJ/mol15.31 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
556.50 kJ/mol397.50 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
31.50 J/mol.K23.80 J/mol.K
9.5
198.1
👆🏻