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Neptunium Curium Comparison


Curium Neptunium comparison


Periodic Table

Symbol
Np   
Cm   

Group Number
Not Available   
Not Available   

Period Number
7   
7   

Block
f block   
f block   

Element Family
Actinide   
Actinide   

CAS Number
7439998   
99+
7440519   
36

Space Group Name
Pnma   
Not Available   

Space Group Number
62.00   
11
Not Available   

Facts

Interesting Facts
Not Available   
  • Curium metal does not occur free in nature.
  • Curium metal is a synthetically produced metal.
  

Sources
Made by Bombarding Uranium with Neutrons, Ores of metals   
Bombarding Plutonium with Helium Ions   

History
  
  

Who Discovered
Edwin McMillan and Philip H. Abelson   
Glenn T. Seaborg, Ralph A. James, Albert Ghiorso   

Discovery
In 1940   
In 1944   

Abundance
  
  

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.
  
  • Curium metal is used to provide power to electrical equipment for space missions.
  

Industrial Uses
NA   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys, Nuclear Research, Research Purposes   
Research Purposes   

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

Physical Properties

Melting Point
640.00 °C   
99+
1,340.00 °C   
34

Boiling Point
3,902.00 °C   
13
3,110.00 °C   
30

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 Properties

Chemical Formula
Np   
Cm   

Isotopes
  
  

Known Isotopes
20   
19
15   
24

Electronegativity
  
  

Pauling Electronegativity
1.36   
29
1.30   
32

Allred Rochow Electronegativity
1.22   
26
1.20   
27

Electropositivity
  
  

Pauling Electropositivity
2.64   
25
2.70   
22

Ionization Energies
  
  

1st Energy Level
604.50 kJ/mol   
99+
581.00 kJ/mol   
99+

2nd Energy Level
1,128.00 kJ/mol   
99+
1,196.00 kJ/mol   
99+

3rd Energy Level
1,997.00 kJ/mol   
99+
2,026.00 kJ/mol   
99+

4th Energy Level
3,242.00 kJ/mol   
99+
3,550.00 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   

Atomic Properties

Atomic Number
93   
25
96   
22

Electron Configuration
[Rn] 5f4 6d1 7s2   
[Rn] 5f7 6d1 7s2   

Crystal Structure
Orthorhombic (ORTH)   
Double Hexagonal Close Packed (DHCP)   

Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100   
DHCP-Crystal-Structure-of-Curium.jpg#100   

Atom
  
  

Number of Protons
93   
25
96   
22

Number of Neutrons
144   
14
151   
10

Number of Electrons
93   
25
96   
22

Radius of an Atom
  
  

Atomic Radius
155.00 pm   
30
174.00 pm   
20

Covalent Radius
190.00 pm   
18
169.00 pm   
26

Van der Waals Radius
221.00 pm   
22
200.00 pm   
28

Atomic Weight
237.00 amu   
22
247.00 amu   
18

Atomic Volume
11.62 cm3/mol   
99+
18.28 cm3/mol   
26

Adjacent Atomic Numbers
  
  

Previous Element
Uranium
  
Americium
  

Next Element
Plutonium
  
Berkelium
  

Valence Electron Potential
96.00 (-eV)   
9
44.50 (-eV)   
38

Lattice Constant
666.30 pm   
3
Not Available   

Lattice Angles
π/2, π/2, π/2   
NA   

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

Density At Room Temperature
19.38 g/cm3   
14
13.51 g/cm3   
25

Density When Liquid (at m.p.)
Not Available   
13.85 g/cm3   
10

Tensile Strength
125.00 MPa   
14
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 2000 K
0.11 (Pa)   
17
Not Available   

Elasticity properties
  
  

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
Ductile   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
20.25   
6
13.51   
17

Magnetic Ordering
Paramagnetic   
Antiferromagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Unknown   

Resistivity
1.22 nΩ·m   
99+
1.25 nΩ·m   
99+

Electrical Conductivity
0.01 106/cm Ω   
99+
Not Available   

Thermal Properties

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+
Not Available   

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
Not Available   
Not Available   

Enthalpy
  
  

Enthalpy of Fusion
3.20 kJ/mol   
99+
15.00 kJ/mol   
21

Standard Molar Entropy
Not Available   
Not Available   

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