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Neptunium Chromium Comparison


Chromium Neptunium comparison


Periodic Table

Symbol
Np   
Cr   

Group Number
Not Available   
6   
12

Period Number
7   
4   

Block
f block   
d block   

Element Family
Actinide   
Transition Metal   

CAS Number
7439998   
99+
7440473   
39

Space Group Name
Pnma   
Im_ 3m   

Space Group Number
62.00   
11
229.00   
1

Facts

Interesting Facts
Not Available   
  • 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
Made by Bombarding Uranium with Neutrons, Ores of metals   
Found in Minerals, Mining, Ores of metals, Ores of Minerals   

History
  
  

Who Discovered
Edwin McMillan and Philip H. Abelson   
Louis Nicolas Vauquelin   

Discovery
In 1940   
In Between 1797 - 1798   

Abundance
  
  

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

Abundance In Sun
~-9999 %   
~0.002 %   
7

Abundance In Meteorites
Not Available   
0.30 %   
7

Abundance In Earth's Crust
Not Available   
0.01 %   
13

Abundance In Oceans
Not Available   
0.00 %   
16

Abundance In Humans
Not Available   
0.00 %   
16

Uses

Uses & Benefits
  • Currently known uses of Neptunium metal are limited to research purpose only.
  • Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  
  • 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
NA   
Automobile Industry, Chemical Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys, Nuclear Research, Research Purposes   
Alloys   

Biological Properties
  
  

Toxicity
Toxic   
Highly Toxic   

Present in Human Body
No   
Yes   

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

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

Physical Properties

Melting Point
640.00 °C   
99+
1,857.00 °C   
14

Boiling Point
3,902.00 °C   
13
2,672.00 °C   
39

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silver   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
8.50   
1

Brinell Hardness
Not Available   
687.00 MPa   
16

Vickers Hardness
Not Available   
1,060.00 MPa   
10

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

Optical Properties
  
  

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
Np   
Cr   

Isotopes
  
  

Known Isotopes
20   
19
21   
18

Electronegativity
  
  

Pauling Electronegativity
1.36   
29
1.66   
18

Sanderson Electronegativity
Not Available   
1.66   
14

Allred Rochow Electronegativity
1.22   
26
1.56   
10

Allen Electronegativity
Not Available   
1.65   
19

Electropositivity
  
  

Pauling Electropositivity
2.64   
25
2.34   
36

Ionization Energies
  
  

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

2nd Energy Level
1,128.00 kJ/mol   
99+
28,750.00 kJ/mol   
1

3rd Energy Level
1,997.00 kJ/mol   
99+
34,230.00 kJ/mol   
1

4th Energy Level
3,242.00 kJ/mol   
99+
37,066.00 kJ/mol   
1

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Electrochemical Equivalent
1.77 g/amp-hr   
39
0.32 g/amp-hr   
99+

Electron Work Function
Not Available   
4.50 eV   
14

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

Atomic Properties

Atomic Number
93   
25
24   
99+

Electron Configuration
[Rn] 5f4 6d1 7s2   
[Ar] 3d5 4s1   

Crystal Structure
Orthorhombic (ORTH)   
Body Centered Cubic (BCC)   

Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100   
BCC-Crystal-Structure-.jpg#100   

Atom
  
  

Number of Protons
93   
25
24   
99+

Number of Neutrons
144   
14
28   
99+

Number of Electrons
93   
25
24   
99+

Radius of an Atom
  
  

Atomic Radius
155.00 pm   
30
128.00 pm   
99+

Covalent Radius
190.00 pm   
18
139.00 pm   
99+

Van der Waals Radius
221.00 pm   
22
200.00 pm   
28

Atomic Weight
237.00 amu   
22
52.00 amu   
99+

Atomic Volume
11.62 cm3/mol   
99+
7.23 cm3/mol   
99+

Adjacent Atomic Numbers
  
  

Previous Element
Uranium
  
Vanadium
  

Next Element
Plutonium
  
Manganese
  

Valence Electron Potential
96.00 (-eV)   
9
170.00 (-eV)   
4

Lattice Constant
666.30 pm   
3
291.00 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
19.38 g/cm3   
14
7.19 g/cm3   
99+

Density When Liquid (at m.p.)
Not Available   
6.30 g/cm3   
40

Tensile Strength
125.00 MPa   
14
689.00 MPa   
7

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

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

Vapor Pressure at 2000 K
0.11 (Pa)   
17
774.00 (Pa)   
1

Elasticity properties
  
  

Shear Modulus
Not Available   
115.00 GPa   
9

Bulk Modulus
Not Available   
160.00 GPa   
11

Young's Modulus
Not Available   
279.00 GPa   
8

Poisson Ratio
Not Available   
0.21   
32

Other Mechanical Properties
Ductile   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
20.25   
6
7.19   
99+

Magnetic Ordering
Paramagnetic   
Antiferromagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
NA   

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

Electrical Conductivity
0.01 106/cm Ω   
99+
0.08 106/cm Ω   
25

Electron Affinity
Not Available   
64.30 kJ/mol   
15

Thermal Properties

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

Molar Heat Capacity
29.46 J/mol·K   
8
23.35 J/mol·K   
99+

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
Not Available   
4.90 µm/(m·K)   
99+

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
348.80 kJ/mol   
24

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

Enthalpy of Atomization
Not Available   
397.50 kJ/mol   
21

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

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