Calcium vs Rhodium
Periodic Table
Symbol
Ca
Rh
Group Number
2
16
9
9
Period Number
4
5
Block
s block
d block
Element Family
Alkaline Earth
Transition Metal
CAS Number
7440702
21
7440166
99+
Space Group Name
Fm_ 3m
Fm_ 3m
Space Group Number
225.00
2
225.00
2
Facts
Interesting Facts
- Calcium ranks 5th rank in the list of earth’s abundance Percentage.
- It is found in the compound state.
- Gypsum or calcium sulfate is used as plaster and plaster of paris.
- 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, Found in Minerals, Mining, Ores of Minerals
Earth's crust, Found As a By-product, Found in Minerals, Mining
History
Who Discovered
Humphry Davy
William Hyde Wollaston
Discovery
In 1808
In 1804
Abundance
Abundance In Universe
7 * 10-3 %
3
6 * 10-8 %
26
Abundance In Sun
~0.007 %
4
~0.0000002 %
25
Abundance In Meteorites
1.10 %
4
0.00 %
36
Abundance In Earth's Crust
5.00 %
3
0.00 %
99+
Abundance In Oceans
0.00 %
5
Not Available
Abundance In Humans
1.40 %
1
Not Available
Uses
Uses & Benefits
- It is used as a reducing agent while preparing metals like thorium and uranium. It is also used as an alloying agent for metals such as aluminum, copper & lead.
- Calcium carbonate or lime stone is used in cement.
- 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
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
Medical Uses
Dentistry, Pharmaceutical Industry
NA
Other Uses
Alloys
Alloys
Biological Properties
Toxicity
Non Toxic
NA
Present in Human Body
Yes
No
In Blood
60.50 Blood/mg dm-3
4
Not Available
In Bone
170,000.00 p.p.m.
1
Not Available
Physical Properties
Melting Point
839.00 °C
99+
1,966.00 °C
12
Boiling Point
1,484.00 °C
99+
3,727.00 °C
17
Appearance
Physical State
Solid
Solid
Color
Gray
Silvery White
Luster
NA
Metallic
Hardness
Mohs Hardness
1.75
17
6.00
6
Brinell Hardness
170.00 MPa
99+
980.00 MPa
9
Vickers Hardness
Not Available
1,100.00 MPa
9
Speed of Sound
3,810.00 m/s
19
4,700.00 m/s
15
Optical Properties
Reflectivity
Not Available
84.00 %
4
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
Ca
Rh
Isotopes
Known Isotopes
19
20
16
23
Electronegativity
Pauling Electronegativity
1.00
99+
2.28
3
Sanderson Electronegativity
0.95
24
Not Available
Allred Rochow Electronegativity
1.04
34
1.45
16
Mulliken-Jaffe Electronegativity
1.08
17
Not Available
Allen Electronegativity
1.03
39
1.56
24
Electropositivity
Pauling Electropositivity
3.00
9
1.72
99+
Ionization Energies
1st Energy Level
589.80 kJ/mol
99+
719.70 kJ/mol
29
2nd Energy Level
1,145.40 kJ/mol
99+
1,740.00 kJ/mol
26
3rd Energy Level
4,912.40 kJ/mol
7
2,997.00 kJ/mol
27
4th Energy Level
6,491.00 kJ/mol
7
Not Available
5th Energy Level
8,153.00 kJ/mol
7
Not Available
6th Energy Level
10,496.00 kJ/mol
8
Not Available
7th Energy level
12,270.00 kJ/mol
12
Not Available
8th Energy Level
14,206.00 kJ/mol
15
Not Available
9th Energy Level
18,191.00 kJ/mol
12
Not Available
10th Energy Level
20,385.00 kJ/mol
16
Not Available
11th Energy Level
57,110.00 kJ/mol
3
Not Available
12th Energy Level
63,410.00 kJ/mol
3
Not Available
13th Energy Level
70,110.00 kJ/mol
3
Not Available
14th Energy Level
78,890.00 kJ/mol
4
Not Available
15th Energy Level
86,310.00 kJ/mol
5
Not Available
16th Energy Level
94,000.00 kJ/mol
6
Not Available
17th Energy Level
104,900.00 kJ/mol
7
Not Available
18th Energy Level
111,711.00 kJ/mol
8
Not Available
Electrochemical Equivalent
0.75 g/amp-hr
99+
1.28 g/amp-hr
99+
Electron Work Function
2.87 eV
38
4.98 eV
6
Other Chemical Properties
Chemical Stability, Flammability, Ionization, Solubility
Anti Corrosion, Ionization, Radioactive Isotopes
Atomic Properties
Atomic Number
20
99+
45
99+
Electron Configuration
[Ar] 4s2
[Kr] 4d8 5s1
Crystal Structure
Face Centered Cubic (FCC)
Face Centered Cubic (FCC)
Crystal Lattice
FCC-Crystal-Structure-of-Calcium.jpg#100
FCC-Crystal-Structure-of-Rhodium.jpg#100
Atom
Number of Protons
20
99+
45
99+
Number of Neutrons
20
99+
58
99+
Number of Electrons
20
99+
45
99+
Radius of an Atom
Atomic Radius
197.00 pm
6
134.00 pm
99+
Covalent Radius
176.00 pm
22
142.00 pm
99+
Van der Waals Radius
231.00 pm
19
200.00 pm
28
Atomic Weight
40.08 amu
99+
102.91 amu
99+
Atomic Volume
29.90 cm3/mol
7
8.30 cm3/mol
99+
Adjacent Atomic Numbers
Valence Electron Potential
29.00 (-eV)
99+
64.00 (-eV)
22
Lattice Constant
558.84 pm
9
380.34 pm
27
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
1.55 g/cm3
99+
12.41 g/cm3
28
Density When Liquid (at m.p.)
1.38 g/cm3
99+
10.70 g/cm3
14
Tensile Strength
Not Available
951.00 MPa
5
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
25.50 (Pa)
3
Not Available
Vapor Pressure at 2000 K
Not Available
0.02 (Pa)
19
Elasticity properties
Shear Modulus
7.40 GPa
99+
150.00 GPa
6
Bulk Modulus
17.00 GPa
99+
275.00 GPa
5
Young's Modulus
20.00 GPa
99+
380.00 GPa
5
Poisson Ratio
0.31
13
0.26
22
Other Mechanical Properties
NA
Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
4.58
99+
12.41
20
Magnetic Ordering
Diamagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
Conductor
Resistivity
33.60 nΩ·m
99+
43.30 nΩ·m
99+
Electrical Conductivity
0.30 106/cm Ω
6
0.21 106/cm Ω
8
Electron Affinity
2.37 kJ/mol
39
109.70 kJ/mol
7
Thermal Properties
Specific Heat
0.63 J/(kg K)
7
0.24 J/(kg K)
22
Molar Heat Capacity
25.93 J/mol·K
34
24.98 J/mol·K
99+
Thermal Conductivity
201.00 W/m·K
5
150.00 W/m·K
9
Critical Temperature
Not Available
Not Available
Thermal Expansion
22.30 µm/(m·K)
19
8.20 µm/(m·K)
99+
Enthalpy
Enthalpy of Vaporization
150.00 kJ/mol
99+
495.40 kJ/mol
12
Enthalpy of Fusion
8.54 kJ/mol
99+
21.76 kJ/mol
10
Enthalpy of Atomization
184.00 kJ/mol
99+
556.50 kJ/mol
12
Standard Molar Entropy
41.60 J/mol.K
36
31.50 J/mol.K
99+
|
||
|
||
|
