Symbol
Rh
Cd
Group Number
912
0
17
👆🏻
Period Number
55
2
7
👆🏻
Block
d block
d block
Element Family
Transition Metal
Transition Metal
CAS Number
74401667440439
7429905
54386242
👆🏻
Space Group Name
Fm_ 3m
P63/mmc
Space Group Number
225.00194.00
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.
- Naturally occurring minor elements include Cadmium.
- Cadmium is released into atmosphere to control volcanic eruption and forest fires.
- It is used for electroplating of Steel for corrosion resistance.
- It can absorb neutrons and used in nuclear reactor to control atomic fission.
Sources
Earth's crust, Found As a By-product, Found in Minerals, Mining
Found As a By-product, Found in Minerals, Mining
History
Who Discovered
William Hyde Wollaston
Karl Samuel Leberecht Hermann and Friedrich Stromeyer
Discovery
In 1804
In 1817
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 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
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 has very limited uses as it is a toxic metal and it can cause birth defects, cancer, etc.
-
Almost 80% of Cadmium metal is used in Nickel cadmium Batteries and now it is getting replaced with nickel hydride.
Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
-
-
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
-
Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.01 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.1.80 p.p.m.
0
170000
👆🏻
Melting Point
1,966.00 °C320.90 °C
-38.83
3410
👆🏻
Boiling Point
3,727.00 °C765.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery Bluish-Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
6.002.00
0.2
8.5
👆🏻
Brinell Hardness
980.00 MPa203.00 MPa
0.14
3490
👆🏻
Vickers Hardness
1,100.00 MPa90.00 MPa
0
3920
👆🏻
Speed of Sound
4,700.00 m/s2,310.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
2.401.71
0.155
3.41
👆🏻
Reflectivity
84.00 %67.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Rh
Cd
Isotopes
Known Isotopes
1634
0
38
👆🏻
Electronegativity
Pauling Electronegativity
2.281.69
0
2.6
👆🏻
Sanderson Electronegativity
2.281.98
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.451.46
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
2.281.53
0.62
2.48
👆🏻
Allen Electronegativity
1.561.52
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
1.722.31
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
719.70 kJ/mol867.80 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,740.00 kJ/mol1,631.40 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,997.00 kJ/mol3,616.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
7,197.00 kJ/mol867.80 kJ/mol
375.7
37066
👆🏻
5th Energy Level
7,197.00 kJ/mol4,040.00 kJ/mol
392
97510
👆🏻
6th Energy Level
7,197.00 kJ/mol8,640.00 kJ/mol
1007
105800
👆🏻
7th Energy level
7,197.00 kJ/mol8,640.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
3,480.00 kJ/mol8,640.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,090.00 kJ/mol8,670.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
7,197.00 kJ/mol8,650.00 kJ/mol
392
144300
👆🏻
11th Energy Level
7,197.00 kJ/mol8,670.00 kJ/mol
392
169988
👆🏻
12th Energy Level
7,190.00 kJ/mol86,400.00 kJ/mol
0
189368
👆🏻
13th Energy Level
7,190.00 kJ/mol8,640.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
7,197.00 kJ/mol8,650.00 kJ/mol
380
86450
👆🏻
15th Energy Level
71,900.00 kJ/mol86,400.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
71,900.00 kJ/mol86,400.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
719.70 kJ/mol864.90 kJ/mol
375.7
122200
👆🏻
18th Energy Level
7,197.00 kJ/mol8,670.00 kJ/mol
0
134810
👆🏻
19th Energy Level
719.70 kJ/mol867.80 kJ/mol
375.7
148700
👆🏻
20th Energy Level
719.00 kJ/mol865.00 kJ/mol
0
171200
👆🏻
21st Energy Level
719.70 kJ/mol8,670.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
719.00 kJ/mol864.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
719.70 kJ/mol864.90 kJ/mol
357.6
198800
👆🏻
24th Energy Level
719.70 kJ/mol864.90 kJ/mol
297.3
195200
👆🏻
25th Energy Level
719.00 kJ/mol864.00 kJ/mol
0
121900
👆🏻
26th Energy Level
719.70 kJ/mol864.90 kJ/mol
357.6
127700
👆🏻
27th Energy Level
719.70 kJ/mol864.90 kJ/mol
0
133800
👆🏻
28th Energy Level
719.70 kJ/mol864.90 kJ/mol
297.3
139800
👆🏻
29th Energy Level
719.70 kJ/mol864.90 kJ/mol
0
148100
👆🏻
30th Energy Level
719.00 kJ/mol864.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.28 g/amp-hr2.10 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.98 eV4.22 eV
2.14
6
👆🏻
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Number
4548
3
117
👆🏻
Electron Configuration
[Kr] 4d8 5s1
[Kr] 4d10 5s2
Crystal Structure
Face Centered Cubic (FCC)
Hexagonal Close Packed (HCP)
Crystal Lattice
Atom
Number of Protons
4548
3
117
👆🏻
Number of Neutrons
5864
4
285
👆🏻
Number of Electrons
4548
3
117
👆🏻
Radius of an Atom
Atomic Radius
134.00 pm151.00 pm
0
348
👆🏻
Covalent Radius
142.00 pm144.00 pm
0
260
👆🏻
Van der Waals Radius
200.00 pm158.00 pm
0
348
👆🏻
Atomic Weight
102.91 amu112.41 amu
6.94
294
👆🏻
Atomic Volume
8.30 cm3/mol13.10 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
64.00 (-eV)30.00 (-eV)
0
392.42
👆🏻
Lattice Constant
380.34 pm297.94 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.731.89
0.423
1.9
👆🏻
Density
Density At Room Temperature
12.41 g/cm38.65 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
10.70 g/cm38.00 g/cm3
0.512
41
👆🏻
Tensile Strength
951.00 MPa62.00 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)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
150.00 GPa19.00 GPa
1.3
222
👆🏻
Bulk Modulus
275.00 GPa42.00 GPa
0
462
👆🏻
Young's Modulus
380.00 GPa50.00 GPa
0
528
👆🏻
Poisson Ratio
0.260.30
0.032
0.47
👆🏻
Other Mechanical Properties
Malleable
Ductile, Malleable
Magnetic Characteristics
Specific Gravity
12.418.65
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
Diamagnetic
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
Semiconductor
Resistivity
43.30 nΩ·m72.70 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.21 106/cm Ω0.14 106/cm Ω
0
0.63
👆🏻
Electron Affinity
109.70 kJ/mol0.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.24 J/(kg K)0.23 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
24.98 J/mol·K26.02 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
150.00 W/m·K96.60 W/m·K
0
429
👆🏻
Critical Temperature
2,237.00 K594.00 K
26.3
3695
👆🏻
Thermal Expansion
8.20 µm/(m·K)30.80 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
495.40 kJ/mol100.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
21.76 kJ/mol6.19 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
556.50 kJ/mol113.00 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
31.50 J/mol.K51.80 J/mol.K
9.5
198.1
👆🏻