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Protactinium Curium Comparison


Curium Protactinium comparison


Periodic Table

Symbol
Pa   
Cm   

Group Number
Not Available   
Not Available   

Period Number
7   
7   

Block
f block   
f block   

Element Family
Actinide   
Actinide   

CAS Number
7440133   
99+
7440519   
36

Space Group Name
I4/mmm   
Not Available   

Space Group Number
139.00   
8
Not Available   

Facts

Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Curium metal does not occur free in nature.
  • Curium metal is a synthetically produced metal.
  

Sources
Found in Uranium Ores, Mining, Ores of metals   
Bombarding Plutonium with Helium Ions   

History
  
  

Who Discovered
William Crookes   
Glenn T. Seaborg, Ralph A. James, Albert Ghiorso   

Discovery
In 1900   
In 1944   

Abundance
  
  

Abundance In Earth's Crust
0.00 %   
99+
Not Available   

Abundance In Oceans
0.00 %   
99+
Not Available   

Uses

Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • Curium metal is used to provide power to electrical equipment for space missions.
  

Industrial Uses
NA   
NA   

Medical Uses
NA   
NA   

Other Uses
NA   
Research Purposes   

Biological Properties
  
  

Toxicity
Highly 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
1,568.00 °C   
21
1,340.00 °C   
34

Boiling Point
4,027.00 °C   
12
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
Pa   
Cm   

Isotopes
  
  

Known Isotopes
27   
12
15   
24

Electronegativity
  
  

Pauling Electronegativity
1.50   
27
1.30   
32

Allred Rochow Electronegativity
1.14   
28
1.20   
27

Electropositivity
  
  

Pauling Electropositivity
2.50   
27
2.70   
22

Ionization Energies
  
  

1st Energy Level
568.00 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
1,814.00 kJ/mol   
99+
2,026.00 kJ/mol   
99+

4th Energy Level
2,991.00 kJ/mol   
99+
3,550.00 kJ/mol   
99+

Electrochemical Equivalent
1.72 g/amp-hr   
99+
3.07 g/amp-hr   
16

Electron Work Function
Not Available   
Not Available   

Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity   
Ionization, Radioactive Isotopes   

Atomic Properties

Atomic Number
91   
27
96   
22

Electron Configuration
[Rn] 5f2 6d1 7s2   
[Rn] 5f7 6d1 7s2   

Crystal Structure
Tetragonal (TETR)   
Double Hexagonal Close Packed (DHCP)   

Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
DHCP-Crystal-Structure-of-Curium.jpg#100   

Atom
  
  

Number of Protons
91   
27
96   
22

Number of Neutrons
122   
21
151   
10

Number of Electrons
91   
27
96   
22

Radius of an Atom
  
  

Atomic Radius
163.00 pm   
25
174.00 pm   
20

Covalent Radius
200.00 pm   
11
169.00 pm   
26

Van der Waals Radius
243.00 pm   
11
200.00 pm   
28

Atomic Weight
231.04 amu   
24
247.00 amu   
18

Atomic Volume
15.00 cm3/mol   
34
18.28 cm3/mol   
26

Adjacent Atomic Numbers
  
  

Previous Element
Thorium
  
Americium
  

Next Element
Uranium
  
Berkelium
  

Valence Electron Potential
92.00 (-eV)   
11
44.50 (-eV)   
38

Lattice Constant
392.50 pm   
23
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
15.37 g/cm3   
20
13.51 g/cm3   
25

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

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Elasticity properties
  
  

Poisson Ratio
Not Available   
Not Available   

Other Mechanical Properties
Unknown   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
15.37   
12
13.51   
17

Magnetic Ordering
Paramagnetic   
Antiferromagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Unknown   

Resistivity
177.00 nΩ·m   
21
1.25 nΩ·m   
99+

Electrical Conductivity
0.05 106/cm Ω   
34
Not Available   

Thermal Properties

Specific Heat
0.12 J/(kg K)   
40
Not Available   

Molar Heat Capacity
Not Available   
Not Available   

Thermal Conductivity
47.00 W/m·K   
32
Not Available   

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
9.90 µm/(m·K)   
40
Not Available   

Enthalpy
  
  

Enthalpy of Fusion
12.34 kJ/mol   
28
15.00 kJ/mol   
21

Standard Molar Entropy
198.10 J/mol.K   
1
Not Available   

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