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Protactinium vs Curium


Curium vs Protactinium


Periodic Table

Symbol
Pa  
Cm  

Group Number
3  
15
3  
15

Period Number
7  
7  

Block
f block  
f block  

Element Family
Actinide  
Actinide  

CAS Number
7440133  
99+
7440519  
36

Space Group Name
I4/mmm  
-  

Space Group Number
139.00  
11
225.00  
3

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 Universe
0.00 %  
17
0.00 %  
35

Abundance In Sun
0.00 %  
26
0.00 %  
30

Abundance In Meteorites
-  
0.00 %  
99+

Abundance In Earth's Crust
0.00 %  
99+
0.00 %  
99+

Abundance In Oceans
0.00 %  
99+
-  

Abundance In Humans
0.00 %  
24
0.00 %  
24

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
-  
-  

Medical Uses
-  
-  

Other Uses
-  
Research Purposes  

Biological Properties
  
  

Toxicity
Highly Toxic  
-  

Present in Human Body
No  
No  

In Blood
0.00 Blood/mg dm-3  
40
0.00 Blood/mg dm-3  
40

In Bone
0.00 p.p.m.  
99+
0.00 p.p.m.  
99+

Physical

Melting Point
1,568.00 °C  
21
1,340.00 °C  
34

Boiling Point
4,027.00 °C  
12
3,110.00 °C  
31

Appearance
  
  

Physical State
Solid  
Solid  

Color
Silver  
Silver  

Luster
Metallic  
Metallic  

Hardness
  
  

Mohs Hardness
5.00  
8
2.00  
17

Brinell Hardness
125.00 MPa  
99+
320.00 MPa  
40

Vickers Hardness
220.00 MPa  
99+
461.00 MPa  
37

Speed of Sound
12,400.00 m/s  
3
2,260.00 m/s  
99+

Optical Properties
  
  

Refractive Index
1.60  
33
1.30  
99+

Reflectivity
60.00 %  
23
60.00 %  
23

Allotropes
No  
No  

α Allotropes
-  
-  

β Allotropes
-  
-  

γ Allotropes
-  
-  

Chemical

Chemical Formula
Pa  
Cm  

Isotopes
  
  

Known Isotopes
27  
12
15  
24

Electronegativity
  
  

Pauling Electronegativity
1.50  
28
1.30  
33

Sanderson Electronegativity
1.50  
18
1.30  
25

Allred Rochow Electronegativity
1.14  
29
1.20  
28

Mulliken-Jaffe Electronegativity
1.50  
26
1.30  
33

Allen Electronegativity
1.50  
32
1.30  
40

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+

5th Energy Level
5,120.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

6th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

7th Energy level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

8th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

9th Energy Level
5,120.00 kJ/mol  
99+
6,690.00 kJ/mol  
37

10th Energy Level
5,120.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

11th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

12th Energy Level
5,680.00 kJ/mol  
99+
58,100.00 kJ/mol  
19

13th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

14th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
40

15th Energy Level
56,800.00 kJ/mol  
99+
58,100.00 kJ/mol  
99+

16th Energy Level
56,800.00 kJ/mol  
99+
58,100.00 kJ/mol  
99+

17th Energy Level
568.50 kJ/mol  
99+
581.00 kJ/mol  
99+

18th Energy Level
5,680.00 kJ/mol  
99+
5,810.00 kJ/mol  
99+

19th Energy Level
568.30 kJ/mol  
99+
581.00 kJ/mol  
99+

20th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

21st Energy Level
568.00 kJ/mol  
99+
5,810.00 kJ/mol  
20

22nd Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

23rd Energy Level
568.00 kJ/mol  
99+
5,810.00 kJ/mol  
20

24th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

25th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

26th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

27th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

28th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

29th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

30th Energy Level
568.00 kJ/mol  
99+
581.00 kJ/mol  
99+

Electrochemical Equivalent
1.72 g/amp-hr  
99+
3.07 g/amp-hr  
19

Electron Work Function
5.89 eV  
3
4.50 eV  
19

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

Atomic

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  
22
151  
11

Number of Electrons
91  
27
96  
22

Radius of an Atom
  
  

Atomic Radius
163.00 pm  
27
174.00 pm  
22

Covalent Radius
200.00 pm  
11
169.00 pm  
28

Van der Waals Radius
243.00 pm  
15
200.00 pm  
35

Atomic Weight
231.04 amu  
24
247.00 amu  
18

Atomic Volume
15.00 cm3/mol  
99+
18.28 cm3/mol  
38

Adjacent Atomic Numbers
  
  

Previous Element
Thorium
  
Americium
  

Next Element
Uranium
  
Berkelium
  

Valence Electron Potential
92.00 (-eV)  
11
44.50 (-eV)  
39

Lattice Constant
392.50 pm  
26
336.25 pm  
99+

Lattice Angles
π/2, π/2, π/2  
-  

Lattice C/A Ratio
1.58  
36
1.67  
11

Mechanical

Density
  
  

Density At Room Temperature
15.37 g/cm3  
20
13.51 g/cm3  
26

Density When Liquid (at m.p.)
15.37 g/cm3  
21
13.85 g/cm3  
25

Tensile Strength
80.00 MPa  
29
350.00 MPa  
12

Viscosity
0.00  
25
0.00  
25

Vapor Pressure
  
  

Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.00 (Pa)  
22

Vapor Pressure at 2000 K
0.00 (Pa)  
32
0.00 (Pa)  
24

Elasticity properties
  
  

Shear Modulus
16.00 GPa  
99+
32.00 GPa  
24

Bulk Modulus
47.00 GPa  
26
40.00 GPa  
38

Young's Modulus
47.00 GPa  
99+
0.00 GPa  
99+

Poisson Ratio
0.23  
30
0.35  
9

Other Mechanical Properties
-  
-  

Magnetic

Magnetic Characteristics
  
  

Specific Gravity
15.37  
23
13.51  
28

Magnetic Ordering
Paramagnetic  
Antiferromagnetic  

Permeability
0.00 H/m  
10
0.00 H/m  
17

Susceptibility
0.00  
21
0.00  
24

Electrical Properties
  
  

Electrical Property
Conductor  
-  

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

Electrical Conductivity
0.05 106/cm Ω  
39
0.13 106/cm Ω  
19

Electron Affinity
53.03 kJ/mol  
22
0.00 kJ/mol  
99+

Thermal

Specific Heat
0.12 J/(kg K)  
99+
0.10 J/(kg K)  
99+

Molar Heat Capacity
27.20 J/mol·K  
24
27.50 J/mol·K  
21

Thermal Conductivity
47.00 W/m·K  
32
11.00 W/m·K  
99+

Critical Temperature
1,841.00 K  
25
1,340.00 K  
99+

Thermal Expansion
9.90 µm/(m·K)  
99+
11.60 µm/(m·K)  
99+

Enthalpy
  
  

Enthalpy of Vaporization
481.00 kJ/mol  
17
331.60 kJ/mol  
40

Enthalpy of Fusion
12.34 kJ/mol  
34
15.00 kJ/mol  
22

Enthalpy of Atomization
481.90 kJ/mol  
19
-  

Standard Molar Entropy
198.10 J/mol.K  
1
52.50 J/mol.K  
36

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