Symbol
Cm
  
Np
  
Group Number
Not Available
  
Not Available
  
Period Number
7
  
7
  
Block
f block
  
f block
  
Element Family
Actinide
  
Actinide
  
Space Group Name
Not Available
  
Pnma
  
Space Group Number
Not Available
  
Interesting Facts
- Curium metal does not occur free in nature.
- Curium metal is a synthetically produced metal.
  
Not Available
  
Sources
Bombarding Plutonium with Helium Ions
  
Made by Bombarding Uranium with Neutrons, Ores of metals
  
History
  
  
Who Discovered
Glenn T. Seaborg, Ralph A. James, Albert Ghiorso
  
Edwin McMillan and Philip H. Abelson
  
Discovery
In 1944
  
In 1940
  
Abundance
  
  
Uses & Benefits
- Curium metal is used to provide power to electrical equipment for space missions.
  
- Currently known uses of Neptunium metal are limited to research purpose only.
-
Neptunium’s isotope neptunium-237 is used as a neutron detectors.
  
Industrial Uses
NA
  
NA
  
Medical Uses
NA
  
NA
  
Other Uses
Research Purposes
  
Alloys, Nuclear Research, Research Purposes
  
Biological Properties
  
  
Toxicity
Unknown
  
Toxic
  
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
Melting Point
1,340.00 °C
  
34
Boiling Point
3,110.00 °C
  
30
3,902.00 °C
  
13
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
Cm
  
Np
  
Isotopes
  
  
Electronegativity
  
  
Pauling Electronegativity
Allred Rochow Electronegativity
Electropositivity
  
  
Pauling Electropositivity
Ionization Energies
  
  
1st Energy Level
581.00 kJ/mol
  
99+
604.50 kJ/mol
  
99+
2nd Energy Level
1,196.00 kJ/mol
  
99+
1,128.00 kJ/mol
  
99+
3rd Energy Level
2,026.00 kJ/mol
  
99+
1,997.00 kJ/mol
  
99+
4th Energy Level
3,550.00 kJ/mol
  
99+
3,242.00 kJ/mol
  
99+
Electrochemical Equivalent
3.07 g/amp-hr
  
16
1.77 g/amp-hr
  
39
Electron Work Function
Not Available
  
Not Available
  
Other Chemical Properties
Ionization, Radioactive Isotopes
  
Ionization, Radioactive Isotopes, Radioactivity, Solubility
  
Electron Configuration
[Rn] 5f7 6d1 7s2
  
[Rn] 5f4 6d1 7s2
  
Crystal Structure
Double Hexagonal Close Packed (DHCP)
  
Orthorhombic (ORTH)
  
Crystal Lattice
DHCP-Crystal-Structure-of-Curium.jpg#100
  
ORTH-Crystal-Structure-of-Neptunium.jpg#100
  
Atom
  
  
Radius of an Atom
  
  
Atomic Volume
18.28 cm3/mol
  
26
11.62 cm3/mol
  
99+
Adjacent Atomic Numbers
  
  
Valence Electron Potential
44.50 (-eV)
  
38
Lattice Constant
Not Available
  
Lattice Angles
NA
  
π/2, π/2, π/2
  
Lattice C/A Ratio
Not Available
  
Not Available
  
Density
  
  
Density At Room Temperature
13.51 g/cm3
  
25
19.38 g/cm3
  
14
Density When Liquid (at m.p.)
13.85 g/cm3
  
10
Not Available
  
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
Unknown
  
Ductile
  
Magnetic Characteristics
  
  
Magnetic Ordering
Antiferromagnetic
  
Paramagnetic
  
Electrical Properties
  
  
Electrical Property
Unknown
  
Conductor
  
Electrical Conductivity
Not Available
  
0.01 10
6/cm Ω
  
99+
Specific Heat
Not Available
  
0.12 J/(kg K)
  
40
Molar Heat Capacity
Not Available
  
29.46 J/mol·K
  
8
Thermal Conductivity
Not Available
  
6.30 W/m·K
  
99+
Critical Temperature
Not Available
  
Not Available
  
Thermal Expansion
Not Available
  
Not Available
  
Enthalpy
  
  
Enthalpy of Fusion
15.00 kJ/mol
  
21
3.20 kJ/mol
  
99+
Standard Molar Entropy
Not Available
  
Not Available