Home
Compare Metals


Strontium vs Protactinium


Protactinium vs Strontium


Periodic Table

Symbol
Sr   
Pa   

Group Number
2   
16
Not Available   

Period Number
5   
7   

Block
s block   
f block   

Element Family
Alkaline Earth   
Actinide   

CAS Number
7440246   
99+
7440133   
99+

Space Group Name
Fm_ 3m   
I4/mmm   

Space Group Number
225.00   
2
139.00   
8

Facts

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

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

History
  
  

Who Discovered
William Cruickshank   
William Crookes   

Discovery
In 1787   
In 1900   

Abundance
  
  

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

Abundance In Sun
~0.000005 %   
15
~-9999 %   

Abundance In Meteorites
0.00 %   
15
Not Available   

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

Abundance In Oceans
0.00 %   
4
0.00 %   
99+

Abundance In Humans
0.00 %   
7
Not Available   

Uses

Uses & Benefits
  • 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.
  
  • Currently known uses of Protactinium metal are limited to research purpose only.
  

Industrial Uses
Ammunition Industry, Chemical Industry   
NA   

Medical Uses
NA   
NA   

Other Uses
Alloys   
NA   

Biological Properties
  
  

Toxicity
Non Toxic   
Highly Toxic   

Present in Human Body
Yes   
No   

In Blood
0.03 Blood/mg dm-3   
19
0.00 Blood/mg dm-3   
37

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

Physical Properties

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

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

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
Metallic   
Metallic   

Hardness
  
  

Mohs Hardness
1.50   
18
Not Available   

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
Sr   
Pa   

Isotopes
  
  

Known Isotopes
27   
12
27   
12

Electronegativity
  
  

Pauling Electronegativity
0.95   
99+
1.50   
27

Sanderson Electronegativity
0.72   
27
Not Available   

Allred Rochow Electronegativity
0.99   
37
1.14   
28

Mulliken-Jaffe Electronegativity
1.00   
18
Not Available   

Allen Electronegativity
0.96   
40
Not Available   

Electropositivity
  
  

Pauling Electropositivity
3.05   
7
2.50   
27

Ionization Energies
  
  

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

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

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

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

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

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

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

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

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

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

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

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

Electron Work Function
2.59 eV   
99+
Not Available   

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

Atomic Properties

Atomic Number
38   
99+
91   
27

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

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

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

Atom
  
  

Number of Protons
38   
99+
91   
27

Number of Neutrons
50   
99+
122   
21

Number of Electrons
38   
99+
91   
27

Radius of an Atom
  
  

Atomic Radius
215.00 pm   
5
163.00 pm   
25

Covalent Radius
195.00 pm   
15
200.00 pm   
11

Van der Waals Radius
249.00 pm   
7
243.00 pm   
11

Atomic Weight
87.62 amu   
99+
231.04 amu   
24

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

Adjacent Atomic Numbers
  
  

Previous Element
Rubidium
  
Thorium
  

Next Element
Yttrium
  
Uranium
  

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

Lattice Constant
608.49 pm   
6
392.50 pm   
23

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
2.64 g/cm3   
99+
15.37 g/cm3   
20

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

Tensile Strength
Not Available   
Not Available   

Viscosity
Not Available   
Not Available   

Vapor Pressure
  
  

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

Elasticity properties
  
  

Shear Modulus
6.03 GPa   
99+
Not Available   

Young's Modulus
15.70 GPa   
99+
Not Available   

Poisson Ratio
0.28   
17
Not Available   

Other Mechanical Properties
NA   
Unknown   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
2.64   
99+
15.37   
12

Magnetic Ordering
Paramagnetic   
Paramagnetic   

Electrical Properties
  
  

Electrical Property
NA   
Conductor   

Resistivity
132.00 nΩ·m   
24
177.00 nΩ·m   
21

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

Electron Affinity
5.03 kJ/mol   
38
Not Available   

Thermal Properties

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

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

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

Critical Temperature
Not Available   
Not Available   

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

Enthalpy
  
  

Enthalpy of Vaporization
150.00 kJ/mol   
99+
Not Available   

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

Enthalpy of Atomization
163.20 kJ/mol   
99+
Not Available   

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

Periodic Table >>
<< All

Compare All Metals

All Metals

All Metals


Compare All Metals