Rhodium vs Radium
Periodic Table
Symbol
Rh
Ra
Group Number
9
9
2
16
Period Number
5
7
Block
d block
s block
Element Family
Transition Metal
Alkaline Earth
CAS Number
7440166
99+
7440144
99+
Space Group Name
Fm_ 3m
Im_ 3m
Space Group Number
225.00
2
229.00
1
Facts
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.
- Radium metal is the heaviest metal of Alkaline earth metals column.
- Radium metal is highly radioactive and does not have any stable isotopes.
Sources
Earth's crust, Found As a By-product, Found in Minerals, Mining
Mining, Ores of metals
History
Who Discovered
William Hyde Wollaston
Not Available
Discovery
In 1804
In 1898
Abundance
Abundance In Universe
6 * 10-8 %
26
Not Available
Abundance In Sun
~0.0000002 %
25
~-9999 %
Abundance In Meteorites
0.00 %
36
Not Available
Abundance In Earth's Crust
0.00 %
99+
0.00 %
99+
Abundance In Oceans
Not Available
0.00 %
99+
Abundance In Humans
Not Available
0.00 %
20
Uses
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 a highly radioactive metal; and sometime Radium-223 is used to treat prostate cancer.
- It is used in luminous paints.
Industrial Uses
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
NA
Medical Uses
NA
Pharmaceutical Industry
Other Uses
Alloys
NA
Biological Properties
Toxicity
NA
Highly Toxic
Present in Human Body
No
No
Physical Properties
Melting Point
1,966.00 °C
12
700.00 °C
99+
Boiling Point
3,727.00 °C
17
1,737.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silvery White
Silvery White
Luster
Metallic
Metallic
Hardness
Mohs Hardness
6.00
6
Not Available
Brinell Hardness
980.00 MPa
9
Not Available
Vickers Hardness
1,100.00 MPa
9
Not Available
Speed of Sound
4,700.00 m/s
15
Not Available
Optical Properties
Reflectivity
84.00 %
4
Not Available
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Rh
Ra
Isotopes
Known Isotopes
16
23
33
6
Electronegativity
Pauling Electronegativity
2.28
3
0.90
99+
Allred Rochow Electronegativity
1.45
16
0.97
38
Mulliken-Jaffe Electronegativity
Not Available
0.92
20
Allen Electronegativity
1.56
24
0.89
99+
Electropositivity
Pauling Electropositivity
1.72
99+
3.10
5
Ionization Energies
1st Energy Level
719.70 kJ/mol
29
509.30 kJ/mol
99+
2nd Energy Level
1,740.00 kJ/mol
26
979.00 kJ/mol
99+
3rd Energy Level
2,997.00 kJ/mol
27
Not Available
Electrochemical Equivalent
1.28 g/amp-hr
99+
4.22 g/amp-hr
6
Electron Work Function
4.98 eV
6
Not Available
Other Chemical Properties
Anti Corrosion, Ionization, Radioactive Isotopes
Ionization, Radioactive Isotopes, Radioactivity
Atomic Properties
Atomic Number
45
99+
88
30
Electron Configuration
[Kr] 4d8 5s1
[Rn] 7s2
Crystal Structure
Face Centered Cubic (FCC)
Body Centered Cubic (BCC)
Crystal Lattice
FCC-Crystal-Structure-of-Rhodium.jpg#100
BCC-Crystal-Structure-.jpg#100
Atom
Number of Protons
45
99+
88
30
Number of Neutrons
58
99+
138
16
Number of Electrons
45
99+
88
30
Radius of an Atom
Atomic Radius
134.00 pm
99+
Not Available
Covalent Radius
142.00 pm
99+
221.00 pm
3
Van der Waals Radius
200.00 pm
28
283.00 pm
4
Atomic Weight
102.91 amu
99+
226.00 amu
26
Atomic Volume
8.30 cm3/mol
99+
45.20 cm3/mol
4
Adjacent Atomic Numbers
Valence Electron Potential
64.00 (-eV)
22
20.10 (-eV)
99+
Lattice Constant
380.34 pm
27
514.80 pm
13
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
12.41 g/cm3
28
5.50 g/cm3
99+
Density When Liquid (at m.p.)
10.70 g/cm3
14
Not Available
Tensile Strength
951.00 MPa
5
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.02 (Pa)
19
Not Available
Elasticity properties
Shear Modulus
150.00 GPa
6
Not Available
Bulk Modulus
275.00 GPa
5
Not Available
Young's Modulus
380.00 GPa
5
Not Available
Poisson Ratio
0.26
22
Not Available
Other Mechanical Properties
Malleable
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
12.41
20
5.00
99+
Magnetic Ordering
Paramagnetic
Nonmagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
43.30 nΩ·m
99+
100.00 nΩ·m
31
Electrical Conductivity
0.21 106/cm Ω
8
Not Available
Electron Affinity
109.70 kJ/mol
7
Not Available
Thermal Properties
Specific Heat
0.24 J/(kg K)
22
0.12 J/(kg K)
40
Molar Heat Capacity
24.98 J/mol·K
99+
Not Available
Thermal Conductivity
150.00 W/m·K
9
18.60 W/m·K
99+
Critical Temperature
Not Available
Not Available
Thermal Expansion
8.20 µm/(m·K)
99+
Not Available
Enthalpy
Enthalpy of Vaporization
495.40 kJ/mol
12
Not Available
Enthalpy of Fusion
21.76 kJ/mol
10
Not Available
Enthalpy of Atomization
556.50 kJ/mol
12
163.00 kJ/mol
99+
Standard Molar Entropy
31.50 J/mol.K
99+
71.00 J/mol.K
14
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