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Promethium vs Chromium


Chromium vs Promethium


Periodic Table

Symbol
Pm  
Cr  

Group Number
3  
15
6  
12

Period Number
6  
4  

Block
f block  
d block  

Element Family
Lanthanide  
Transition Metal  

CAS Number
7440122  
99+
7440473  
39

Space Group Name
-  
Im_ 3m  

Space Group Number
194.00  
7
229.00  
2

Facts

Interesting Facts
  • Promethium metal found in Pitchblende.
  • Promethium metal is highly radioactive metal.
  
  • Chromium is highly reactive, hence it is not found free in nature.
  • Ores of Chromites mineral are the major source of Chromium metal.
  • Almost 90% leather tanning is done with the help of chromium.
  

Sources
Found in Minerals, Mining  
Found in Minerals, Mining, Ores of metals, Ores of Minerals  

History
  
  

Who Discovered
Chien Shiung Wu, Emilio Segrè, Hans Bethe  
Louis Nicolas Vauquelin  

Discovery
In 1942  
In Between 1797 - 1798  

Abundance
  
  

Abundance In Universe
0.00 %  
40
0.00 %  
8

Abundance In Sun
-  
0.00 %  
7

Abundance In Meteorites
-  
0.30 %  
7

Abundance In Earth's Crust
0.00 %  
99+
0.01 %  
13

Abundance In Oceans
-  
0.00 %  
16

Abundance In Humans
0.00 %  
24
0.00 %  
19

Uses

Uses & Benefits
  • It is used for research purpose. Very small amount of this metal is used in atomic batteries.
  • Its radioactive decay is used for a phosphor to give off light. The light emitted is converted into electricity.
  
  • It is used to harden the steel and produces a stainless steel and other various alloys.
  • It is also used to give proper finish to polished mirrors. Its chromium plates are used in bathroom fittings.
  

Industrial Uses
-  
Automobile Industry, Chemical Industry  

Medical Uses
-  
-  

Other Uses
-  
Alloys  

Biological Properties
  
  

Toxicity
Non Toxic  
Highly Toxic  

Present in Human Body
No  
Yes  

In Blood
0.00 Blood/mg dm-3  
40
0.11 Blood/mg dm-3  
12

In Bone
0.00 p.p.m.  
99+
0.33 p.p.m.  
25

Physical

Melting Point
1,042.00 °C  
99+
1,857.00 °C  
14

Boiling Point
3,000.00 °C  
32
2,672.00 °C  
99+

Appearance
  
  

Physical State
Solid  
Solid  

Color
-  
Silver  

Luster
Metallic  
Metallic  

Hardness
  
  

Mohs Hardness
-  
8.50  
1

Brinell Hardness
400.00 MPa  
34
687.00 MPa  
18

Vickers Hardness
600.00 MPa  
28
1,060.00 MPa  
17

Speed of Sound
2,260.00 m/s  
99+
5,940.00 m/s  
8

Optical Properties
  
  

Refractive Index
1.70  
27
2.97  
2

Reflectivity
63.00 %  
20
70.00 %  
13

Allotropes
No  
No  

α Allotropes
-  
-  

β Allotropes
-  
-  

γ Allotropes
-  
-  

Chemical

Chemical Formula
Pm  
Cr  

Isotopes
  
  

Known Isotopes
27  
12
21  
18

Electronegativity
  
  

Pauling Electronegativity
1.13  
99+
1.66  
19

Sanderson Electronegativity
1.13  
36
1.66  
17

Allred Rochow Electronegativity
1.07  
33
1.56  
11

Mulliken-Jaffe Electronegativity
1.13  
99+
1.66  
19

Allen Electronegativity
1.13  
99+
1.65  
22

Electropositivity
  
  

Pauling Electropositivity
2.20  
39
2.34  
36

Ionization Energies
  
  

1st Energy Level
540.00 kJ/mol  
99+
26,130.00 kJ/mol  
1

2nd Energy Level
1,050.00 kJ/mol  
99+
28,750.00 kJ/mol  
1

3rd Energy Level
2,150.00 kJ/mol  
99+
34,230.00 kJ/mol  
1

4th Energy Level
3,970.00 kJ/mol  
99+
37,066.00 kJ/mol  
1

5th Energy Level
5,400.00 kJ/mol  
99+
97,510.00 kJ/mol  
1

6th Energy Level
5,400.00 kJ/mol  
99+
105,800.00 kJ/mol  
1

7th Energy level
5,400.00 kJ/mol  
99+
114,300.00 kJ/mol  
1

8th Energy Level
5,400.00 kJ/mol  
99+
125,300.00 kJ/mol  
1

9th Energy Level
5,400.00 kJ/mol  
99+
134,700.00 kJ/mol  
1

10th Energy Level
5,400.00 kJ/mol  
99+
144,300.00 kJ/mol  
1

11th Energy Level
5,400.00 kJ/mol  
99+
26,130.00 kJ/mol  
12

12th Energy Level
5,400.00 kJ/mol  
99+
28,750.00 kJ/mol  
36

13th Energy Level
5,400.00 kJ/mol  
99+
34,230.00 kJ/mol  
10

14th Energy Level
5,400.00 kJ/mol  
99+
37,066.00 kJ/mol  
12

15th Energy Level
54,000.00 kJ/mol  
99+
97,510.00 kJ/mol  
2

16th Energy Level
54,000.00 kJ/mol  
99+
105,800.00 kJ/mol  
2

17th Energy Level
540.50 kJ/mol  
99+
114,300.00 kJ/mol  
3

18th Energy Level
5,400.00 kJ/mol  
99+
125,300.00 kJ/mol  
4

19th Energy Level
540.00 kJ/mol  
99+
134,700.00 kJ/mol  
5

20th Energy Level
540.00 kJ/mol  
99+
144,300.00 kJ/mol  
7

21st Energy Level
540.00 kJ/mol  
99+
157,700.00 kJ/mol  
7

22nd Energy Level
540.00 kJ/mol  
99+
166,090.00 kJ/mol  
6

23rd Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
99+

24th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
32

25th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
34

26th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
33

27th Energy Level
540.00 kJ/mol  
99+
652.90 kJ/mol  
34

28th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
39

29th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
40

30th Energy Level
540.00 kJ/mol  
99+
653.80 kJ/mol  
36

Electrochemical Equivalent
1.80 g/amp-hr  
40
0.32 g/amp-hr  
99+

Electron Work Function
5.30 eV  
5
4.50 eV  
19

Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility  
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility  

Atomic

Atomic Number
61  
99+
24  
99+

Electron Configuration
[Xe] 4f5 6s2  
[Ar] 3d5 4s1  

Crystal Structure
Double Hexagonal Close Packed (DHCP)  
Body Centered Cubic (BCC)  

Crystal Lattice
DHCP-Crystal-Structure-of-Promethium.jpg#100  
BCC-Crystal-Structure-.jpg#100  

Atom
  
  

Number of Protons
61  
99+
24  
99+

Number of Neutrons
84  
99+
28  
99+

Number of Electrons
61  
99+
24  
99+

Radius of an Atom
  
  

Atomic Radius
183.00 pm  
12
128.00 pm  
99+

Covalent Radius
199.00 pm  
12
139.00 pm  
99+

Van der Waals Radius
236.00 pm  
20
200.00 pm  
35

Atomic Weight
145.00 amu  
99+
52.00 amu  
99+

Atomic Volume
22.39 cm3/mol  
21
7.23 cm3/mol  
99+

Adjacent Atomic Numbers
  
  

Previous Element
Neodymium
  
Vanadium
  

Next Element
Samarium
  
Manganese
  

Valence Electron Potential
44.10 (-eV)  
40
170.00 (-eV)  
4

Lattice Constant
-  
291.00 pm  
99+

Lattice Angles
-  
π/2, π/2, π/2  

Lattice C/A Ratio
1.63  
14
1.86  
4

Mechanical

Density
  
  

Density At Room Temperature
7.26 g/cm3  
99+
7.19 g/cm3  
99+

Density When Liquid (at m.p.)
7.26 g/cm3  
99+
6.30 g/cm3  
99+

Tensile Strength
75.00 MPa  
30
689.00 MPa  
7

Viscosity
0.00  
25
0.00  
23

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.00 (Pa)  
26

Vapor Pressure at 2000 K
0.00 (Pa)  
31
774.00 (Pa)  
1

Elasticity properties
  
  

Shear Modulus
18.00 GPa  
99+
115.00 GPa  
9

Bulk Modulus
33.00 GPa  
99+
160.00 GPa  
11

Young's Modulus
46.00 GPa  
99+
279.00 GPa  
8

Poisson Ratio
0.28  
17
0.21  
33

Other Mechanical Properties
-  
-  

Magnetic

Magnetic Characteristics
  
  

Specific Gravity
7.26  
99+
7.19  
99+

Magnetic Ordering
Paramagnetic  
Antiferromagnetic  

Permeability
0.00 H/m  
11
0.00 H/m  
17

Susceptibility
0.00  
25
0.00  
10

Electrical Properties
  
  

Electrical Property
Conductor  
-  

Resistivity
0.75 nΩ·m  
99+
125.00 nΩ·m  
27

Electrical Conductivity
0.00 106/cm Ω  
99+
0.08 106/cm Ω  
30

Electron Affinity
50.00 kJ/mol  
26
64.30 kJ/mol  
17

Thermal

Specific Heat
0.18 J/(kg K)  
34
0.45 J/(kg K)  
12

Molar Heat Capacity
27.60 J/mol·K  
20
23.35 J/mol·K  
99+

Thermal Conductivity
17.90 W/m·K  
99+
93.90 W/m·K  
17

Critical Temperature
1,315.00 K  
99+
1,907.00 K  
24

Thermal Expansion
9.00 µm/(m·K)  
99+
4.90 µm/(m·K)  
99+

Enthalpy
  
  

Enthalpy of Vaporization
289.00 kJ/mol  
99+
348.80 kJ/mol  
35

Enthalpy of Fusion
7.50 kJ/mol  
99+
15.31 kJ/mol  
20

Enthalpy of Atomization
310.00 kJ/mol  
99+
397.50 kJ/mol  
27

Standard Molar Entropy
57.00 J/mol.K  
30
23.80 J/mol.K  
99+

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