Neptunium vs Cadmium
Periodic Table
Symbol
Np
Cd
Group Number
Not Available
12
6
Period Number
7
5
Block
f block
d block
Element Family
Actinide
Transition Metal
CAS Number
7439998
99+
7440439
99+
Space Group Name
Pnma
P63/mmc
Space Group Number
62.00
11
194.00
5
Facts
Interesting Facts
Not Available
- Naturally occurring minor elements include Cadmium.
- Cadmium is released into atmosphere to control volcanic eruption and forest fires.
- It is used for electroplating of Steel for corrosion resistance.
- It can absorb neutrons and used in nuclear reactor to control atomic fission.
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals
Found As a By-product, Found in Minerals, Mining
History
Who Discovered
Edwin McMillan and Philip H. Abelson
Karl Samuel Leberecht Hermann and Friedrich Stromeyer
Discovery
In 1940
In 1817
Abundance
Abundance In Universe
Not Available
2 * 10-7 %
22
Abundance In Sun
~-9999 %
~0.0000006 %
21
Abundance In Meteorites
Not Available
0.00 %
31
Abundance In Earth's Crust
Not Available
0.00 %
99+
Abundance In Oceans
Not Available
0.00 %
28
Abundance In Humans
Not Available
0.00 %
11
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 has very limited uses as it is a toxic metal and it can cause birth defects, cancer, etc.
- Almost 80% of Cadmium metal is used in Nickel cadmium Batteries and now it is getting replaced with nickel hydride.
Industrial Uses
NA
Aerospace Industry, Ammunition Industry, Chemical Industry, Electrical Industry, Electronic Industry
Medical Uses
NA
NA
Other Uses
Alloys, Nuclear Research, Research Purposes
Alloys
Biological Properties
Toxicity
Toxic
Toxic
Present in Human Body
No
Yes
In Blood
0.00 Blood/mg dm-3
37
0.01 Blood/mg dm-3
24
In Bone
0.00 p.p.m.
36
1.80 p.p.m.
15
Physical Properties
Melting Point
640.00 °C
99+
320.90 °C
99+
Boiling Point
3,902.00 °C
13
765.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silver
Silvery Bluish-Gray
Luster
Metallic
Metallic
Hardness
Mohs Hardness
Not Available
2.00
16
Brinell Hardness
Not Available
203.00 MPa
39
Speed of Sound
Not Available
2,310.00 m/s
39
Optical Properties
Reflectivity
Not Available
67.00 %
11
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
Cd
Isotopes
Known Isotopes
20
19
34
5
Electronegativity
Pauling Electronegativity
1.36
29
1.69
17
Sanderson Electronegativity
Not Available
1.98
9
Allred Rochow Electronegativity
1.22
26
1.46
15
Mulliken-Jaffe Electronegativity
Not Available
1.53
13
Allen Electronegativity
Not Available
1.52
27
Electropositivity
Pauling Electropositivity
2.64
25
2.31
37
Ionization Energies
1st Energy Level
604.50 kJ/mol
99+
867.80 kJ/mol
11
2nd Energy Level
1,128.00 kJ/mol
99+
1,631.40 kJ/mol
32
3rd Energy Level
1,997.00 kJ/mol
99+
3,616.00 kJ/mol
13
4th Energy Level
3,242.00 kJ/mol
99+
Not Available
Electrochemical Equivalent
1.77 g/amp-hr
39
2.10 g/amp-hr
27
Electron Work Function
Not Available
4.22 eV
22
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Chemical Stability, Anti Corrosion, Ionization, Radioactive Isotopes, Solubility
Atomic Properties
Atomic Number
93
25
48
99+
Electron Configuration
[Rn] 5f4 6d1 7s2
[Kr] 4d10 5s2
Crystal Structure
Orthorhombic (ORTH)
Hexagonal Close Packed (HCP)
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100
HCP-Crystal-Structure-of-Cadmium.jpg#100
Atom
Number of Protons
93
25
48
99+
Number of Neutrons
144
14
64
99+
Number of Electrons
93
25
48
99+
Radius of an Atom
Atomic Radius
155.00 pm
30
151.00 pm
32
Covalent Radius
190.00 pm
18
144.00 pm
40
Van der Waals Radius
221.00 pm
22
158.00 pm
99+
Atomic Weight
237.00 amu
22
112.41 amu
99+
Atomic Volume
11.62 cm3/mol
99+
13.10 cm3/mol
39
Adjacent Atomic Numbers
Valence Electron Potential
96.00 (-eV)
9
30.00 (-eV)
99+
Lattice Constant
666.30 pm
3
297.94 pm
99+
Lattice Angles
π/2, π/2, π/2
π/2, π/2, 2 π/3
Lattice C/A Ratio
Not Available
1.89
1
Mechanical Properties
Density
Density At Room Temperature
19.38 g/cm3
14
8.65 g/cm3
99+
Density When Liquid (at m.p.)
Not Available
8.00 g/cm3
28
Tensile Strength
125.00 MPa
14
62.00 MPa
16
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 2000 K
0.11 (Pa)
17
Not Available
Elasticity properties
Shear Modulus
Not Available
19.00 GPa
35
Bulk Modulus
Not Available
42.00 GPa
29
Young's Modulus
Not Available
50.00 GPa
36
Poisson Ratio
Not Available
0.30
14
Other Mechanical Properties
Ductile
Ductile, Malleable
Magnetic Properties
Magnetic Characteristics
Specific Gravity
20.25
6
8.65
36
Magnetic Ordering
Paramagnetic
Diamagnetic
Electrical Properties
Electrical Property
Conductor
Semiconductor
Resistivity
1.22 nΩ·m
99+
72.70 nΩ·m
36
Electrical Conductivity
0.01 106/cm Ω
99+
0.14 106/cm Ω
15
Electron Affinity
Not Available
0.00 kJ/mol
40
Thermal Properties
Specific Heat
0.12 J/(kg K)
40
0.23 J/(kg K)
26
Molar Heat Capacity
29.46 J/mol·K
8
26.02 J/mol·K
32
Thermal Conductivity
6.30 W/m·K
99+
96.60 W/m·K
16
Critical Temperature
Not Available
Not Available
Thermal Expansion
Not Available
30.80 µm/(m·K)
10
Enthalpy
Enthalpy of Vaporization
Not Available
100.00 kJ/mol
99+
Enthalpy of Fusion
3.20 kJ/mol
99+
6.19 kJ/mol
99+
Enthalpy of Atomization
Not Available
113.00 kJ/mol
99+
Standard Molar Entropy
Not Available
51.80 J/mol.K
27
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