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Protactinium Scandium Comparison


Scandium Protactinium comparison


Periodic Table

Symbol
Pa   
Sc   

Group Number
Not Available   
3   
15

Period Number
7   
4   

Block
f block   
d block   

Element Family
Actinide   
Transition Metal   

CAS Number
7440133   
99+
7440202   
99+

Space Group Name
I4/mmm   
P63/mmc   

Space Group Number
139.00   
8
194.00   
5

Facts

Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Scandium is known as one of the rare earth elements.
  • Scandium metal found in rare minerals called Wolframite .
  

Sources
Found in Uranium Ores, Mining, Ores of metals   
Found in Minerals, Mining, Ores of metals, Ores of Minerals   

History
  
  

Who Discovered
William Crookes   
Lars Fredrik Nilson   

Discovery
In 1900   
In 1879   

Abundance
  
  

Abundance In Universe
Not Available   
3 * 10-6 %   
15

Abundance In Sun
~-9999 %   
~0.000004 %   
16

Abundance In Meteorites
Not Available   
0.00 %   
18

Abundance In Earth's Crust
0.00 %   
99+
0.00 %   
23

Abundance In Oceans
0.00 %   
99+
0.00 %   
32

Uses

Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • Uses of Scandium are limited to research purpose only. However, it has very low density and higher melting point.
  • Its compounds like scandium iodide is used in mercury vapor lamps to produce very bright white light.
  

Industrial Uses
NA   
Electrical Industry, Electronic Industry   

Medical Uses
NA   
NA   

Other Uses
NA   
Alloys   

Biological Properties
  
  

Toxicity
Highly Toxic   
Non Toxic   

Present in Human Body
No   
Yes   

In Blood
0.00 Blood/mg dm-3   
37
0.01 Blood/mg dm-3   
22

In Bone
0.00 p.p.m.   
36
0.00 p.p.m.   
34

Physical Properties

Melting Point
1,568.00 °C   
21
1,539.00 °C   
24

Boiling Point
4,027.00 °C   
12
2,832.00 °C   
35

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silvery White   

Luster
Metallic   
Lustrous   

Hardness
  
  

Brinell Hardness
Not Available   
750.00 MPa   
12

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   
Sc   

Isotopes
  
  

Known Isotopes
27   
12
13   
26

Electronegativity
  
  

Pauling Electronegativity
1.50   
27
1.36   
29

Sanderson Electronegativity
Not Available   
1.02   
21

Allred Rochow Electronegativity
1.14   
28
1.20   
27

Allen Electronegativity
Not Available   
1.19   
36

Electropositivity
  
  

Pauling Electropositivity
2.50   
27
2.64   
25

Ionization Energies
  
  

1st Energy Level
568.00 kJ/mol   
99+
633.10 kJ/mol   
99+

2nd Energy Level
1,128.00 kJ/mol   
99+
1,235.00 kJ/mol   
99+

3rd Energy Level
1,814.00 kJ/mol   
99+
2,388.60 kJ/mol   
99+

4th Energy Level
2,991.00 kJ/mol   
99+
7,090.60 kJ/mol   
6

5th Energy Level
Not Available   
8,843.00 kJ/mol   
6

6th Energy Level
Not Available   
10,679.00 kJ/mol   
7

7th Energy level
Not Available   
13,310.00 kJ/mol   
8

8th Energy Level
Not Available   
15,250.00 kJ/mol   
11

9th Energy Level
Not Available   
17,370.00 kJ/mol   
14

10th Energy Level
Not Available   
21,726.00 kJ/mol   
13

11th Energy Level
Not Available   
24,102.00 kJ/mol   
16

12th Energy Level
Not Available   
66,320.00 kJ/mol   
2

13th Energy Level
Not Available   
73,010.00 kJ/mol   
2

14th Energy Level
Not Available   
80,160.00 kJ/mol   
3

15th Energy Level
Not Available   
89,490.00 kJ/mol   
4

16th Energy Level
Not Available   
97,400.00 kJ/mol   
5

17th Energy Level
Not Available   
105,600.00 kJ/mol   
6

18th Energy Level
Not Available   
117,000.00 kJ/mol   
7

19th Energy Level
Not Available   
124,270.00 kJ/mol   
8

Electrochemical Equivalent
1.72 g/amp-hr   
99+
0.56 g/amp-hr   
99+

Electron Work Function
Not Available   
3.50 eV   
31

Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity   
Corrosion, Flammable, Ionization, Radioactive Isotopes, Solubility   

Atomic Properties

Atomic Number
91   
27
21   
99+

Electron Configuration
[Rn] 5f2 6d1 7s2   
[Ar] 3d1 4s2   

Crystal Structure
Tetragonal (TETR)   
Hexagonal Close Packed (HCP)   

Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
HCP-Crystal-Structure-of-Scandium.jpg#100   

Atom
  
  

Number of Protons
91   
27
21   
99+

Number of Neutrons
122   
21
24   
99+

Number of Electrons
91   
27
21   
99+

Radius of an Atom
  
  

Atomic Radius
163.00 pm   
25
162.00 pm   
26

Covalent Radius
200.00 pm   
11
170.00 pm   
25

Van der Waals Radius
243.00 pm   
11
211.00 pm   
25

Atomic Weight
231.04 amu   
24
44.96 amu   
99+

Atomic Volume
15.00 cm3/mol   
34
15.00 cm3/mol   
34

Adjacent Atomic Numbers
  
  

Previous Element
Thorium
  
Calcium
  

Next Element
Uranium
  
Titanium
  

Valence Electron Potential
92.00 (-eV)   
11
58.00 (-eV)   
24

Lattice Constant
392.50 pm   
23
330.90 pm   
99+

Lattice Angles
π/2, π/2, π/2   
π/2, π/2, 2 π/3   

Lattice C/A Ratio
Not Available   
1.59   
7

Mechanical Properties

Density
  
  

Density At Room Temperature
15.37 g/cm3   
20
2.99 g/cm3   
99+

Density When Liquid (at m.p.)
Not Available   
2.80 g/cm3   
99+

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
Not Available   
0.00 (Pa)   
22

Vapor Pressure at 2000 K
Not Available   
91.30 (Pa)   
3

Elasticity properties
  
  

Shear Modulus
Not Available   
29.10 GPa   
24

Bulk Modulus
Not Available   
56.60 GPa   
21

Young's Modulus
Not Available   
74.40 GPa   
26

Poisson Ratio
Not Available   
0.28   
18

Other Mechanical Properties
Unknown   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
15.37   
12
2.99   
99+

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
Conductor   

Resistivity
177.00 nΩ·m   
21
562.00 nΩ·m   
10

Electrical Conductivity
0.05 106/cm Ω   
34
0.02 106/cm Ω   
99+

Electron Affinity
Not Available   
18.10 kJ/mol   
33

Thermal Properties

Specific Heat
0.12 J/(kg K)   
40
0.60 J/(kg K)   
8

Molar Heat Capacity
Not Available   
25.52 J/mol·K   
37

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

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
9.90 µm/(m·K)   
40
10.20 µm/(m·K)   
39

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
314.20 kJ/mol   
28

Enthalpy of Fusion
12.34 kJ/mol   
28
14.10 kJ/mol   
25

Enthalpy of Atomization
Not Available   
343.00 kJ/mol   
28

Standard Molar Entropy
198.10 J/mol.K   
1
34.60 J/mol.K   
99+

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