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Neptunium vs Chromium

Neptunium
Chromium
Chromium vs Neptunium


Periodic Table
Symbol
Np  
Cr  
Group Number
3  
15
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  
14
229.00  
2
Facts
Interesting Facts
Neptunium was the first transuranium element to be discovered.  
  • 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
0.00 %  
40
0.00 %  
8
Abundance In Sun
0.00 %  
26
0.00 %  
7
Abundance In Meteorites
0.00 %  
99+
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
  • 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
-  
Automobile Industry, Chemical Industry  
Medical Uses
-  
-  
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  
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
640.00 °C  
99+
1,857.00 °C  
14
Boiling Point
3,902.00 °C  
13
2,672.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silver  
Silver  
Luster
Metallic  
Metallic  
Hardness
  
  
Mohs Hardness
6.00  
6
8.50  
1
Brinell Hardness
622.00 MPa  
23
687.00 MPa  
18
Vickers Hardness
640.00 MPa  
23
1,060.00 MPa  
17
Speed of Sound
2,260.00 m/s  
99+
5,940.00 m/s  
8
Optical Properties
  
  
Refractive Index
1.30  
99+
2.97  
2
Reflectivity
64.00 %  
19
70.00 %  
13
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Np  
Cr  
Isotopes
  
  
Known Isotopes
20  
19
21  
18
Electronegativity
  
  
Pauling Electronegativity
1.36  
30
1.66  
19
Sanderson Electronegativity
1.36  
23
1.66  
17
Allred Rochow Electronegativity
1.22  
27
1.56  
11
Mulliken-Jaffe Electronegativity
1.36  
31
1.66  
19
Allen Electronegativity
1.36  
37
1.65  
22
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
6,180.00 kJ/mol  
99+
97,510.00 kJ/mol  
1
6th Energy Level
5,785.00 kJ/mol  
99+
105,800.00 kJ/mol  
1
7th Energy level
6,040.00 kJ/mol  
99+
114,300.00 kJ/mol  
1
8th Energy Level
6,040.00 kJ/mol  
99+
125,300.00 kJ/mol  
1
9th Energy Level
6,180.00 kJ/mol  
99+
134,700.00 kJ/mol  
1
10th Energy Level
6,180.00 kJ/mol  
99+
144,300.00 kJ/mol  
1
11th Energy Level
6,180.00 kJ/mol  
99+
26,130.00 kJ/mol  
12
12th Energy Level
61,800.00 kJ/mol  
13
28,750.00 kJ/mol  
36
13th Energy Level
6,180.00 kJ/mol  
40
34,230.00 kJ/mol  
10
14th Energy Level
6,180.00 kJ/mol  
29
37,066.00 kJ/mol  
12
15th Energy Level
60,600.00 kJ/mol  
99+
97,510.00 kJ/mol  
2
16th Energy Level
60,420.00 kJ/mol  
31
105,800.00 kJ/mol  
2
17th Energy Level
604.00 kJ/mol  
99+
114,300.00 kJ/mol  
3
18th Energy Level
6,040.00 kJ/mol  
99+
125,300.00 kJ/mol  
4
19th Energy Level
604.50 kJ/mol  
99+
134,700.00 kJ/mol  
5
20th Energy Level
604.00 kJ/mol  
99+
144,300.00 kJ/mol  
7
21st Energy Level
6,040.00 kJ/mol  
17
157,700.00 kJ/mol  
7
22nd Energy Level
604.00 kJ/mol  
40
166,090.00 kJ/mol  
6
23rd Energy Level
6,040.00 kJ/mol  
18
653.80 kJ/mol  
99+
24th Energy Level
604.50 kJ/mol  
99+
653.80 kJ/mol  
32
25th Energy Level
604.00 kJ/mol  
99+
653.80 kJ/mol  
34
26th Energy Level
604.00 kJ/mol  
99+
653.80 kJ/mol  
33
27th Energy Level
604.00 kJ/mol  
99+
652.90 kJ/mol  
34
28th Energy Level
604.00 kJ/mol  
99+
653.80 kJ/mol  
39
29th Energy Level
604.00 kJ/mol  
99+
653.80 kJ/mol  
40
30th Energy Level
604.00 kJ/mol  
99+
653.80 kJ/mol  
36
Electrochemical Equivalent
1.77 g/amp-hr  
99+
0.32 g/amp-hr  
99+
Electron Work Function
4.90 eV  
12
4.50 eV  
19
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Anti Corrosion, Chemical Stability, Ionization, Radioactive Isotopes, Solubility  
Atomic
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  
15
28  
99+
Number of Electrons
93  
25
24  
99+
Radius of an Atom
  
  
Atomic Radius
155.00 pm  
32
128.00 pm  
99+
Covalent Radius
190.00 pm  
18
139.00 pm  
99+
Van der Waals Radius
221.00 pm  
27
200.00 pm  
35
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
1.43  
99+
1.86  
4
Mechanical
Density
  
  
Density At Room Temperature
19.38 g/cm3  
14
7.19 g/cm3  
99+
Density When Liquid (at m.p.)
20.25 g/cm3  
10
6.30 g/cm3  
99+
Tensile Strength
125.00 MPa  
26
689.00 MPa  
7
Viscosity
0.00  
25
0.00  
23
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
22
0.00 (Pa)  
26
Vapor Pressure at 2000 K
0.11 (Pa)  
17
774.00 (Pa)  
1
Elasticity properties
  
  
Shear Modulus
5.60 GPa  
99+
115.00 GPa  
9
Bulk Modulus
180.00 GPa  
9
160.00 GPa  
11
Young's Modulus
46.00 GPa  
99+
279.00 GPa  
8
Poisson Ratio
0.26  
22
0.21  
33
Other Mechanical Properties
Ductile  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
20.25  
15
7.19  
99+
Magnetic Ordering
Paramagnetic  
Antiferromagnetic  
Permeability
0.00 H/m  
6
0.00 H/m  
17
Susceptibility
0.00  
24
0.00  
10
Electrical Properties
  
  
Electrical Property
Conductor  
-  
Resistivity
1.22 nΩ·m  
99+
125.00 nΩ·m  
27
Electrical Conductivity
0.01 106/cm Ω  
99+
0.08 106/cm Ω  
30
Electron Affinity
118.60 kJ/mol  
6
64.30 kJ/mol  
17
Thermal
Specific Heat
0.12 J/(kg K)  
99+
0.45 J/(kg K)  
12
Molar Heat Capacity
29.46 J/mol·K  
10
23.35 J/mol·K  
99+
Thermal Conductivity
6.30 W/m·K  
99+
93.90 W/m·K  
17
Critical Temperature
913.00 K  
99+
1,907.00 K  
24
Thermal Expansion
13.30 µm/(m·K)  
35
4.90 µm/(m·K)  
99+
Enthalpy
  
  
Enthalpy of Vaporization
336.00 kJ/mol  
39
348.80 kJ/mol  
35
Enthalpy of Fusion
3.20 kJ/mol  
99+
15.31 kJ/mol  
20
Enthalpy of Atomization
275.30 kJ/mol  
99+
397.50 kJ/mol  
27
Standard Molar Entropy
64.00 J/mol.K  
21
23.80 J/mol.K  
99+
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