Symbol
Rh
  
Au
  
Period Number
5
  
6
  
Block
d block
  
d block
  
Element Family
Transition Metal
  
Transition Metal
  
Space Group Name
Fm_ 3m
  
Fm_ 3m
  
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.
  
- It is found in copper ores and from the crust of the earth.
- It is the most malleable and ductile metal.
- Gold alloys are used in Dentistry as fillings, crowning, clips, etc. It is also used as an artificial limb joints.
  
Sources
Earth's crust, Found As a By-product, Found in Minerals, Mining
  
Earth's crust, Mining, Ores of metals
  
History
  
  
Who Discovered
William Hyde Wollaston
  
Unknown
  
Discovery
In 1804
  
Before 6000 BCE
  
Abundance
  
  
Abundance In Sun
~0.0000002 %
  
25
~0.0000001 %
  
26
Abundance In Earth's Crust
Abundance In Oceans
Not Available
  
Abundance In Humans
Not Available
  
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.
  
- Gold metal is mainly used for Jewelry, bullion, coinage, etc.
- It is used in the art, decoration, ornaments, etc. It is also used for electroplating process.
  
Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Chemical Industry, Clothing Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
Dentistry, Pharmaceutical Industry
  
Other Uses
Alloys
  
Alloys, Bullion, Coinage, Jewellery, Sculptures, Statues
  
Biological Properties
  
  
Toxicity
NA
  
Non Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
Not Available
  
0.00 Blood/mg dm-3
  
35
In Bone
Not Available
  
0.02 p.p.m.
  
30
Melting Point
1,966.00 °C
  
12
1,064.43 °C
  
99+
Boiling Point
3,727.00 °C
  
17
2,807.00 °C
  
36
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silvery White
  
Gold
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
Brinell Hardness
194.00 MPa
  
99+
Vickers Hardness
1,100.00 MPa
  
9
Speed of Sound
4,700.00 m/s
  
15
2,030.00 m/s
  
99+
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Rh
  
Au
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
719.70 kJ/mol
  
29
890.10 kJ/mol
  
8
2nd Energy Level
1,740.00 kJ/mol
  
26
1,980.00 kJ/mol
  
12
3rd Energy Level
2,997.00 kJ/mol
  
27
Not Available
  
Electrochemical Equivalent
1.28 g/amp-hr
  
99+
2.45 g/amp-hr
  
21
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
  
Chemical Stability, Ionization, Solubility
  
Electron Configuration
[Kr] 4d8 5s1
  
[Xe] 4f14 5d10 6s1
  
Crystal Structure
Face Centered Cubic (FCC)
  
Face Centered Cubic (FCC)
  
Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100
  
FCC-Crystal-Structure-of-Gold.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
102.91 amu
  
99+
Atomic Volume
8.30 cm3/mol
  
99+
10.20 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
64.00 (-eV)
  
22
43.40 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Density
  
  
Density At Room Temperature
12.41 g/cm3
  
28
19.30 g/cm3
  
15
Density When Liquid (at m.p.)
10.70 g/cm3
  
14
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 1000 K
Not Available
  
Elasticity properties
  
  
Other Mechanical Properties
Malleable
  
Ductile, Malleable
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Diamagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
43.30 nΩ·m
  
99+
Electrical Conductivity
0.21 106/cm Ω
  
8
0.45 106/cm Ω
  
3
Electron Affinity
109.70 kJ/mol
  
7
222.80 kJ/mol
  
1
Specific Heat
0.24 J/(kg K)
  
22
0.13 J/(kg K)
  
39
Molar Heat Capacity
24.98 J/mol·K
  
99+
25.42 J/mol·K
  
40
Thermal Conductivity
150.00 W/m·K
  
9
318.00 W/m·K
  
3
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
8.20 µm/(m·K)
  
99+
14.20 µm/(m·K)
  
26
Enthalpy
  
  
Enthalpy of Vaporization
495.40 kJ/mol
  
12
324.40 kJ/mol
  
27
Enthalpy of Fusion
21.76 kJ/mol
  
10
12.55 kJ/mol
  
27
Enthalpy of Atomization
556.50 kJ/mol
  
12
364.00 kJ/mol
  
25
Standard Molar Entropy
31.50 J/mol.K
  
99+
47.40 J/mol.K
  
32