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Protactinium vs Strontium


Strontium vs Protactinium


Periodic Table

Symbol
Pa   
Sr   

Group Number
Not Available   
2   
16

Period Number
7   
5   

Block
f block   
s block   

Element Family
Actinide   
Alkaline Earth   

CAS Number
7440133   
99+
7440246   
99+

Space Group Name
I4/mmm   
Fm_ 3m   

Space Group Number
139.00   
8
225.00   
2

Facts

Interesting Facts
  • Protactinium metal has 29 isotopes.
  • Isotopes of Protactinium-231 used in nuclear weapon.
  
  • Strontium element is softer than Calcium.
  • Silvery Strontium turns yellow, if exposed to air.
  

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

History
  
  

Who Discovered
William Crookes   
William Cruickshank   

Discovery
In 1900   
In 1787   

Abundance
  
  

Abundance In Universe
Not Available   
4 * 10-6 %   
14

Abundance In Sun
~-9999 %   
~0.000005 %   
15

Abundance In Meteorites
Not Available   
0.00 %   
15

Abundance In Earth's Crust
0.00 %   
99+
0.04 %   
10

Abundance In Oceans
0.00 %   
99+
0.00 %   
4

Abundance In Humans
Not Available   
0.00 %   
7

Uses

Uses & Benefits
  • Currently known uses of Protactinium metal are limited to research purpose only.
  
  • Strontium metal is used to producing ferrite magnets as well as refining zinc.
  • By-product of nuclear reactors called Strontium-90 is a radioactive isotope; it is absorbed by tissues and destroys bone marrow and cancer growth.
  

Industrial Uses
NA   
Ammunition Industry, Chemical 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
0.03 Blood/mg dm-3   
19

In Bone
0.00 p.p.m.   
36
140.00 p.p.m.   
7

Physical Properties

Melting Point
1,568.00 °C   
21
769.00 °C   
99+

Boiling Point
4,027.00 °C   
12
1,384.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silver   
Silvery White   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
Not Available   
1.50   
18

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   
Sr   

Isotopes
  
  

Known Isotopes
27   
12
27   
12

Electronegativity
  
  

Pauling Electronegativity
1.50   
27
0.95   
99+

Sanderson Electronegativity
Not Available   
0.72   
27

Allred Rochow Electronegativity
1.14   
28
0.99   
37

Mulliken-Jaffe Electronegativity
Not Available   
1.00   
18

Allen Electronegativity
Not Available   
0.96   
40

Electropositivity
  
  

Pauling Electropositivity
2.50   
27
3.05   
7

Ionization Energies
  
  

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

2nd Energy Level
1,128.00 kJ/mol   
99+
1,064.20 kJ/mol   
99+

3rd Energy Level
1,814.00 kJ/mol   
99+
4,138.00 kJ/mol   
10

4th Energy Level
2,991.00 kJ/mol   
99+
5,500.00 kJ/mol   
13

5th Energy Level
Not Available   
6,910.00 kJ/mol   
18

6th Energy Level
Not Available   
8,760.00 kJ/mol   
18

7th Energy level
Not Available   
10,230.00 kJ/mol   
19

8th Energy Level
Not Available   
11,800.00 kJ/mol   
19

9th Energy Level
Not Available   
15,600.00 kJ/mol   
17

10th Energy Level
Not Available   
17,100.00 kJ/mol   
19

11th Energy Level
Not Available   
31,270.00 kJ/mol   
6

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

Electron Work Function
Not Available   
2.59 eV   
99+

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

Atomic Properties

Atomic Number
91   
27
38   
99+

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

Crystal Structure
Tetragonal (TETR)   
Face Centered Cubic (FCC)   

Crystal Lattice
TETR-Crystal-Structure-of-Protactinium.jpg#100   
FCC-Crystal-Structure-of-Strontium.jpg#100   

Atom
  
  

Number of Protons
91   
27
38   
99+

Number of Neutrons
122   
21
50   
99+

Number of Electrons
91   
27
38   
99+

Radius of an Atom
  
  

Atomic Radius
163.00 pm   
25
215.00 pm   
5

Covalent Radius
200.00 pm   
11
195.00 pm   
15

Van der Waals Radius
243.00 pm   
11
249.00 pm   
7

Atomic Weight
231.04 amu   
24
87.62 amu   
99+

Atomic Volume
15.00 cm3/mol   
34
33.70 cm3/mol   
6

Adjacent Atomic Numbers
  
  

Previous Element
Thorium
  
Rubidium
  

Next Element
Uranium
  
Yttrium
  

Valence Electron Potential
92.00 (-eV)   
11
25.70 (-eV)   
99+

Lattice Constant
392.50 pm   
23
608.49 pm   
6

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

Lattice C/A Ratio
Not Available   
Not Available   

Mechanical Properties

Density
  
  

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

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

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

Vapor Pressure at 1000 K
Not Available   
121.00 (Pa)   
1

Elasticity properties
  
  

Shear Modulus
Not Available   
6.03 GPa   
99+

Young's Modulus
Not Available   
15.70 GPa   
99+

Poisson Ratio
Not Available   
0.28   
17

Other Mechanical Properties
Unknown   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
15.37   
12
2.64   
99+

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
Conductor   
NA   

Resistivity
177.00 nΩ·m   
21
132.00 nΩ·m   
24

Electrical Conductivity
0.05 106/cm Ω   
34
0.08 106/cm Ω   
26

Electron Affinity
Not Available   
5.03 kJ/mol   
38

Thermal Properties

Specific Heat
0.12 J/(kg K)   
40
0.30 J/(kg K)   
18

Molar Heat Capacity
Not Available   
26.40 J/mol·K   
28

Thermal Conductivity
47.00 W/m·K   
32
35.40 W/m·K   
37

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
9.90 µm/(m·K)   
40
22.50 µm/(m·K)   
18

Enthalpy
  
  

Enthalpy of Vaporization
Not Available   
150.00 kJ/mol   
99+

Enthalpy of Fusion
12.34 kJ/mol   
28
9.16 kJ/mol   
38

Enthalpy of Atomization
Not Available   
163.20 kJ/mol   
99+

Standard Molar Entropy
198.10 J/mol.K   
1
55.00 J/mol.K   
26

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