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Strontium vs Polonium


Polonium vs Strontium


Periodic Table

Symbol
Sr   
Po   

Group Number
2   
16
16   
2

Period Number
5   
6   

Block
s block   
p block   

Element Family
Alkaline Earth   
Post-​Transition   

CAS Number
7440246   
99+
7440086   
99+

Space Group Name
Fm_ 3m   
Pm-3m   

Space Group Number
225.00   
2
221.00   
3

Facts

Interesting Facts
  • Strontium element is softer than Calcium.
  • Silvery Strontium turns yellow, if exposed to air.
  
  • Polonium was the first radioactive element to be discovered.
  • Polonium element and its compounds are highly radioactive.
  • Its alloy with Beryllium provides source of neutrons.
  

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

History
  
  

Who Discovered
William Cruickshank   
Pierre Curie and Marie Curie   

Discovery
In 1787   
In 1898   

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
Not Available   

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.
  
  • Polonium metal has different Allotropes, it is used in antistatic devices and for research purpose.
  • A 1 gram of Polonium can reach a temperature of 500°C, hence it is used as a heat source for space equipment.
  

Industrial Uses
Ammunition Industry, Chemical Industry   
Aerospace Industry, Ammunition Industry   

Medical Uses
NA   
NA   

Other Uses
Alloys   
Alloys   

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+
254.00 °C   
99+

Boiling Point
1,384.00 °C   
99+
962.00 °C   
99+

Appearance
  
  

Physical State
Solid   
Solid   

Color
Silvery White   
Silver   

Luster
Metallic   
NA   

Hardness
  
  

Mohs Hardness
1.50   
18
Not Available   

Speed of Sound
Not Available   
Not Available   

Optical Properties
  
  

Allotropes
No   
Yes   

α Allotropes
Not Available   
α-polonium   

β Allotropes
Not Available   
β-polonium   

γ Allotropes
Not Available   
Not Available   

Chemical Properties

Chemical Formula
Sr   
Po   

Isotopes
  
  

Known Isotopes
27   
12
29   
10

Electronegativity
  
  

Pauling Electronegativity
0.95   
99+
2.00   
7

Sanderson Electronegativity
0.72   
27
Not Available   

Allred Rochow Electronegativity
0.99   
37
1.76   
2

Mulliken-Jaffe Electronegativity
1.00   
18
2.48   
1

Allen Electronegativity
0.96   
40
2.19   
2

Electropositivity
  
  

Pauling Electropositivity
3.05   
7
2.00   
99+

Ionization Energies
  
  

1st Energy Level
549.50 kJ/mol   
99+
812.10 kJ/mol   
14

2nd Energy Level
1,064.20 kJ/mol   
99+
Not Available   

3rd Energy Level
4,138.00 kJ/mol   
10
Not Available   

4th Energy Level
5,500.00 kJ/mol   
13
Not Available   

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+
3.90 g/amp-hr   
8

Electron Work Function
2.59 eV   
99+
Not Available   

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

Atomic Properties

Atomic Number
38   
99+
84   
32

Electron Configuration
[Kr] 5s2   
[Xe] 4f14 5d10 6s2 6p4   

Crystal Structure
Face Centered Cubic (FCC)   
Monoclinic (MON)   

Crystal Lattice
FCC-Crystal-Structure-of-Strontium.jpg#100   
MON-Crystal-Structure-of-Polonium.jpg#100   

Atom
  
  

Number of Protons
38   
99+
84   
32

Number of Neutrons
50   
99+
125   
19

Number of Electrons
38   
99+
84   
32

Radius of an Atom
  
  

Atomic Radius
215.00 pm   
5
168.00 pm   
23

Covalent Radius
195.00 pm   
15
140.00 pm   
99+

Van der Waals Radius
249.00 pm   
7
197.00 pm   
29

Atomic Weight
87.62 amu   
99+
209.00 amu   
28

Atomic Volume
33.70 cm3/mol   
6
22.23 cm3/mol   
13

Adjacent Atomic Numbers
  
  

Previous Element
Rubidium
  
Bismuth
  

Next Element
Yttrium
  
Francium
  

Valence Electron Potential
25.70 (-eV)   
99+
Not Available   

Lattice Constant
608.49 pm   
6
335.90 pm   
99+

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+
9.20 g/cm3   
99+

Density When Liquid (at m.p.)
2.38 g/cm3   
99+
9.40 g/cm3   
19

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   
NA   

Magnetic Properties

Magnetic Characteristics
  
  

Specific Gravity
2.64   
99+
9.32   
31

Magnetic Ordering
Paramagnetic   
Nonmagnetic   

Electrical Properties
  
  

Electrical Property
NA   
Conductor   

Resistivity
132.00 nΩ·m   
24
0.40 nΩ·m   
99+

Electrical Conductivity
0.08 106/cm Ω   
26
0.02 106/cm Ω   
99+

Electron Affinity
5.03 kJ/mol   
38
183.30 kJ/mol   
3

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
26.40 J/mol·K   
28

Thermal Conductivity
35.40 W/m·K   
37
20.00 W/m·K   
99+

Critical Temperature
Not Available   
Not Available   

Thermal Expansion
22.50 µm/(m·K)   
18
23.50 µm/(m·K)   
16

Enthalpy
  
  

Enthalpy of Vaporization
150.00 kJ/mol   
99+
60.30 kJ/mol   
99+

Enthalpy of Fusion
9.16 kJ/mol   
38
13.00 kJ/mol   
26

Enthalpy of Atomization
163.20 kJ/mol   
99+
134.00 kJ/mol   
99+

Standard Molar Entropy
55.00 J/mol.K   
26
Not Available   

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