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