Symbol
Np
  
Cs
  
Group Number
Not Available
  
Period Number
7
  
6
  
Block
f block
  
s block
  
Element Family
Actinide
  
Alkali
  
Space Group Name
Pnma
  
Im_ 3m
  
Interesting Facts
Not Available
  
Not Available
  
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals
  
Earth's crust, Found in Minerals, Mining, Ores of Minerals
  
History
  
  
Who Discovered
Edwin McMillan and Philip H. Abelson
  
Robert Bunsen and Gustav Kirchhoff
  
Discovery
In 1940
  
In 1860
  
Abundance
  
  
Abundance In Universe
Not Available
  
Abundance In Sun
~-9999 %
  
~0.0000008 %
  
20
Abundance In Meteorites
Not Available
  
Abundance In Earth's Crust
Not Available
  
Abundance In Oceans
Not Available
  
Abundance In Humans
Not Available
  
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.
  
- The most common use of cesium metal is as a drilling fluid. It is also used in optical glass manufacturing.
-
In vacuum tubes and radiation monitor equipment this metal is used as a catalyst promoter.
  
Industrial Uses
NA
  
Aerospace Industry, Automobile Industry, Electrical Industry, Electronic Industry
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research, Research Purposes
  
Alloys
  
Biological Properties
  
  
Toxicity
Toxic
  
Mildly Toxic
  
Present in Human Body
No
  
Yes
  
In Blood
0.00 Blood/mg dm-3
  
37
0.00 Blood/mg dm-3
  
28
In Bone
0.00 p.p.m.
  
36
0.05 p.p.m.
  
26
Boiling Point
3,902.00 °C
  
13
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silvery Gold
  
Luster
Metallic
  
NA
  
Hardness
  
  
Mohs Hardness
Not Available
  
Brinell Hardness
Not Available
  
Speed of Sound
Not Available
  
Not Available
  
Optical Properties
  
  
Allotropes
No
  
No
  
α Allotropes
Not Available
  
Not Available
  
β Allotropes
Not Available
  
Not Available
  
γ Allotropes
Not Available
  
Not Available
  
Chemical Formula
Np
  
Cs
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Sanderson Electronegativity
Not Available
  
Allred Rochow Electronegativity
Mulliken-Jaffe Electronegativity
Not Available
  
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
604.50 kJ/mol
  
99+
375.70 kJ/mol
  
99+
2nd Energy Level
1,128.00 kJ/mol
  
99+
2,234.30 kJ/mol
  
8
3rd Energy Level
1,997.00 kJ/mol
  
99+
3,400.00 kJ/mol
  
16
4th Energy Level
3,242.00 kJ/mol
  
99+
Not Available
  
Electrochemical Equivalent
1.77 g/amp-hr
  
39
4.96 g/amp-hr
  
3
Electron Work Function
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Chemical Stability, Corrosion, Ionization, Radioactive Isotopes, Solubility
  
Electron Configuration
[Rn] 5f4 6d1 7s2
  
[Xe] 6s1
  
Crystal Structure
Orthorhombic (ORTH)
  
Body Centered Cubic (BCC)
  
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100
  
BCC-Crystal-Structure-.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Weight
132.91 amu
  
99+
Atomic Volume
11.62 cm3/mol
  
99+
71.07 cm3/mol
  
1
Adjacent Atomic Numbers
  
  
Valence Electron Potential
8.62 (-eV)
  
99+
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
19.38 g/cm3
  
14
1.93 g/cm3
  
99+
Density When Liquid (at m.p.)
Not Available
  
1.84 g/cm3
  
99+
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Bulk Modulus
Not Available
  
Young's Modulus
Not Available
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
Ductile
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Semiconductor
  
Resistivity
205.00 nΩ·m
  
17
Electrical Conductivity
0.01 106/cm Ω
  
99+
0.05 106/cm Ω
  
35
Electron Affinity
Not Available
  
45.50 kJ/mol
  
25
Specific Heat
0.12 J/(kg K)
  
40
0.24 J/(kg K)
  
23
Molar Heat Capacity
29.46 J/mol·K
  
8
32.21 J/mol·K
  
4
Thermal Conductivity
6.30 W/m·K
  
99+
35.90 W/m·K
  
36
Critical Temperature
Not Available
  
Thermal Expansion
Not Available
  
97.00 µm/(m·K)
  
1
Enthalpy
  
  
Enthalpy of Vaporization
Not Available
  
65.90 kJ/mol
  
99+
Enthalpy of Fusion
3.20 kJ/mol
  
99+
2.10 kJ/mol
  
99+
Enthalpy of Atomization
Not Available
  
78.20 kJ/mol
  
99+
Standard Molar Entropy
Not Available
  
85.20 J/mol.K
  
3