Symbol
Np
  
Bk
  
Group Number
Not Available
  
Not Available
  
Period Number
7
  
7
  
Block
f block
  
f block
  
Element Family
Actinide
  
Actinide
  
Space Group Name
Pnma
  
P63/mmc
  
Interesting Facts
Not Available
  
- X-ray Diffraction- different compounds of Berkelium metals are identified using it.
Commercial uses of Berkelium metal are not yet discovered.
  
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals
  
Bombarding Americium with Alpha Particles.
  
History
  
  
Who Discovered
Edwin McMillan and Philip H. Abelson
  
Lawrence Berkeley National Laboratory
  
Discovery
In 1940
  
In 1949
  
Abundance
  
  
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.
  
- This metal is very rare and has no commercial uses.
  
Industrial Uses
NA
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Alloys, Nuclear Research, Research Purposes
  
NA
  
Biological Properties
  
  
Toxicity
Toxic
  
Unknown
  
Present in Human Body
No
  
No
  
In Blood
0.00 Blood/mg dm-3
  
37
0.00 Blood/mg dm-3
  
37
In Bone
0.00 p.p.m.
  
36
0.00 p.p.m.
  
36
Boiling Point
3,902.00 °C
  
13
2,627.00 °C
  
40
Appearance
  
  
Physical State
Solid
  
Solid
  
Color
Silver
  
Silver
  
Luster
Metallic
  
Metallic
  
Hardness
  
  
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
  
Bk
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Allen Electronegativity
Not Available
  
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
604.50 kJ/mol
  
99+
601.00 kJ/mol
  
99+
2nd Energy Level
1,128.00 kJ/mol
  
99+
1,186.00 kJ/mol
  
99+
3rd Energy Level
1,997.00 kJ/mol
  
99+
2,152.00 kJ/mol
  
99+
4th Energy Level
3,242.00 kJ/mol
  
99+
3,434.00 kJ/mol
  
99+
Electrochemical Equivalent
1.77 g/amp-hr
  
39
3.07 g/amp-hr
  
16
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Ionization, Radioactive Isotopes, Radioactivity
  
Electron Configuration
[Rn] 5f4 6d1 7s2
  
[Rn] 5f9 7s2
  
Crystal Structure
Orthorhombic (ORTH)
  
Double Hexagonal Close Packed (DHCP)
  
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100
  
DHCP-Crystal-Structure-of-Berkelium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Covalent Radius
Not Available
  
Van der Waals Radius
Not Available
  
Atomic Volume
11.62 cm3/mol
  
99+
Not Available
  
Adjacent Atomic Numbers
  
  
Valence Electron Potential
45.50 (-eV)
  
36
Lattice Angles
π/2, π/2, π/2
  
π/2, π/2, 2 π/3
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
19.38 g/cm3
  
14
14.78 g/cm3
  
22
Density When Liquid (at m.p.)
Not Available
  
13.25 g/cm3
  
11
Tensile Strength
Not Available
  
Viscosity
Not Available
  
Not Available
  
Vapor Pressure
  
  
Vapor Pressure at 2000 K
Not Available
  
Elasticity properties
  
  
Poisson Ratio
Not Available
  
Not Available
  
Other Mechanical Properties
Ductile
  
NA
  
Magnetic Characteristics
  
  
Magnetic Ordering
Paramagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Conductor
  
Conductor
  
Resistivity
Not Available
  
Electrical Conductivity
0.01 10
6/cm Ω
  
99+
Not Available
  
Specific Heat
0.12 J/(kg K)
  
40
Not Available
  
Molar Heat Capacity
29.46 J/mol·K
  
8
Not Available
  
Thermal Conductivity
6.30 W/m·K
  
99+
10.00 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
Not Available
  
Not Available
  
Enthalpy
  
  
Enthalpy of Fusion
3.20 kJ/mol
  
99+
Not Available
  
Standard Molar Entropy
Not Available
  
Not Available