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Chromium Polonium Comparison


Polonium Chromium comparison


Periodic Table

Symbol
Cr   
Po   

Group Number
6   
12
16   
2

Period Number
4   
6   

Block
d block   
p block   

Element Family
Transition Metal   
Post-​Transition   

CAS Number
7440473   
39
7440086   
99+

Space Group Name
Im_ 3m   
Pm-3m   

Space Group Number
229.00   
1
221.00   
3

Facts

Interesting Facts
  • 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.
  
  • Polonium was the first radioactive element to be discovered.
  • Polonium element and its compounds are highly radioactive.
  • Its alloy with Beryllium provides source of neutrons.
  

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

History
  
  

Who Discovered
Louis Nicolas Vauquelin   
Pierre Curie and Marie Curie   

Discovery
In Between 1797 - 1798   
In 1898   

Abundance
  
  

Abundance In Universe
1.5 * 10-3 %   
7
Not Available   

Abundance In Sun
~0.002 %   
7
~-9999 %   

Abundance In Meteorites
0.30 %   
7
Not Available   

Abundance In Earth's Crust
0.01 %   
13
Not Available   

Abundance In Oceans
0.00 %   
16
0.00 %   
99+

Abundance In Humans
0.00 %   
16
Not Available   

Uses

Uses & Benefits
  • 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.
  
  • Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
  • A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
  

Industrial Uses
Automobile Industry, Chemical Industry   
Aerospace Industry, Ammunition Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys   

Biological Properties
  
  

Toxicity
Highly Toxic   
Highly Toxic   

Present in Human Body
Yes   
No   

In Blood
0.11 Blood/mg dm-3   
12
0.00 Blood/mg dm-3   
37

In Bone
0.33 p.p.m.   
21
0.00 p.p.m.   
36

Physical Properties

Melting Point
1,857.00 °C   
14
254.00 °C   
99+

Boiling Point
2,672.00 °C   
39
962.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silver   

Luster
Metallic   
NA   

Hardness
  
  

Mohs Hardness
8.50   
1
Not Available   

Brinell Hardness
687.00 MPa   
16
Not Available   

Vickers Hardness
1,060.00 MPa   
10
Not Available   

Speed of Sound
5,940.00 m/s   
5
Not Available   

Optical Properties
  
  

Allotropes
No   
Yes   

α Allotropes
Not Available   
α-polonium   

β Allotropes
Not Available   
β-polonium   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Cr   
Po   

Isotopes
  
  

Known Isotopes
21   
18
29   
10

Electronegativity
  
  

Pauling Electronegativity
1.66   
18
2.00   
7

Sanderson Electronegativity
1.66   
14
Not Available   

Allred Rochow Electronegativity
1.56   
10
1.76   
2

Mulliken-Jaffe Electronegativity
Not Available   
2.48   
1

Allen Electronegativity
1.65   
19
2.19   
2

Electropositivity
  
  

Pauling Electropositivity
2.34   
36
2.00   
99+

Ionization Energies
  
  

1st Energy Level
26,130.00 kJ/mol   
1
812.10 kJ/mol   
14

2nd Energy Level
28,750.00 kJ/mol   
1
Not Available   

3rd Energy Level
34,230.00 kJ/mol   
1
Not Available   

4th Energy Level
37,066.00 kJ/mol   
1
Not Available   

5th Energy Level
97,510.00 kJ/mol   
1
Not Available   

6th Energy Level
105,800.00 kJ/mol   
1
Not Available   

7th Energy level
114,300.00 kJ/mol   
1
Not Available   

8th Energy Level
125,300.00 kJ/mol   
1
Not Available   

9th Energy Level
134,700.00 kJ/mol   
1
Not Available   

10th Energy Level
144,300.00 kJ/mol   
1
Not Available   

11th Energy Level
26,130.00 kJ/mol   
12
Not Available   

12th Energy Level
28,750.00 kJ/mol   
13
Not Available   

13th Energy Level
34,230.00 kJ/mol   
10
Not Available   

14th Energy Level
37,066.00 kJ/mol   
12
Not Available   

15th Energy Level
97,510.00 kJ/mol   
1
Not Available   

16th Energy Level
105,800.00 kJ/mol   
2
Not Available   

17th Energy Level
114,300.00 kJ/mol   
3
Not Available   

18th Energy Level
125,300.00 kJ/mol   
4
Not Available   

19th Energy Level
134,700.00 kJ/mol   
5
Not Available   

20th Energy Level
144,300.00 kJ/mol   
7
Not Available   

21st Energy Level
157,700.00 kJ/mol   
7
Not Available   

22nd Energy Level
166,090.00 kJ/mol   
6
Not Available   

Electrochemical Equivalent
0.32 g/amp-hr   
99+
3.90 g/amp-hr   
8

Electron Work Function
4.50 eV   
14
Not Available   

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

Atomic Properties

Atomic Number
24   
99+
84   
32

Electron Configuration
[Ar] 3d5 4s1   
[Xe] 4f14 5d10 6s2 6p4   

Crystal Structure
Body Centered Cubic (BCC)   
Monoclinic (MON)   

Crystal Lattice
BCC-Crystal-Structure-.jpg#100   
MON-Crystal-Structure-of-Polonium.jpg#100   

Atom
  
  

Number of Protons
24   
99+
84   
32

Number of Neutrons
28   
99+
125   
19

Number of Electrons
24   
99+
84   
32

Radius of an Atom
  
  

Atomic Radius
128.00 pm   
99+
168.00 pm   
23

Covalent Radius
139.00 pm   
99+
140.00 pm   
99+

Van der Waals Radius
200.00 pm   
28
197.00 pm   
29

Atomic Weight
52.00 amu   
99+
209.00 amu   
28

Atomic Volume
7.23 cm3/mol   
99+
22.23 cm3/mol   
13

Adjacent Atomic Numbers
  
  

Previous Element
Vanadium
  
Bismuth
  

Next Element
Manganese
  
Francium
  

Valence Electron Potential
170.00 (-eV)   
4
Not Available   

Lattice Constant
291.00 pm   
99+
335.90 pm   
99+

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
7.19 g/cm3   
99+
9.20 g/cm3   
99+

Density When Liquid (at m.p.)
6.30 g/cm3   
40
9.40 g/cm3   
19

Tensile Strength
689.00 MPa   
7
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)   
24
Not Available   

Vapor Pressure at 2000 K
774.00 (Pa)   
1
Not Available   

Elasticity properties
  
  

Shear Modulus
115.00 GPa   
9
Not Available   

Bulk Modulus
160.00 GPa   
11
Not Available   

Young's Modulus
279.00 GPa   
8
Not Available   

Poisson Ratio
0.21   
32
Not Available   

Other Mechanical Properties
NA   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
7.19   
99+
9.32   
31

Magnetic Ordering
Antiferromagnetic   
Nonmagnetic   

Electrical Properties
  
  

Electrical Property
NA   
Conductor   

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

Electrical Conductivity
0.08 106/cm Ω   
25
0.02 106/cm Ω   
99+

Electron Affinity
64.30 kJ/mol   
15
183.30 kJ/mol   
3

Thermal Properties

Specific Heat
0.45 J/(kg K)   
12
0.12 J/(kg K)   
40

Molar Heat Capacity
23.35 J/mol·K   
99+
26.40 J/mol·K   
28

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
4.90 µm/(m·K)   
99+
23.50 µm/(m·K)   
16

Enthalpy
  
  

Enthalpy of Vaporization
348.80 kJ/mol   
24
60.30 kJ/mol   
99+

Enthalpy of Fusion
15.31 kJ/mol   
20
13.00 kJ/mol   
26

Enthalpy of Atomization
397.50 kJ/mol   
21
134.00 kJ/mol   
99+

Standard Molar Entropy
23.80 J/mol.K   
99+
Not Available   

Summary >>
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