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Francium vs Mendelevium

Francium
Mendelevium
Mendelevium vs Francium


Periodic Table
Symbol
Fr  
Md  
Group Number
1  
17
3  
15
Period Number
7  
7  
Block
s block  
f block  
Element Family
Alkali  
Actinide  
CAS Number
7440735  
18
7440111  
99+
Space Group Name
-  
-  
Space Group Number
225.00  
3
194.00  
7
Facts
Interesting Facts
  • 223 Francium has the longest half life at 21.8.
  • Francium metal is produced by alpha decay in 227Actinium 227.
  
  • Mendelevium metal is synthetically produced metal.
  • Mendelevium metal has been produced in only trace amount.
  
Sources
Formed by Decay Process, Mining  
Bombarding Einsteinium with Helium Ions  
History
  
  
Who Discovered
Marguerite Perey  
Lawrence Berkeley National Laboratory  
Discovery
In 1939  
In 1955  
Abundance
  
  
Abundance In Universe
0.00 %  
40
0.00 %  
40
Abundance In Sun
0.00 %  
30
-  
Abundance In Meteorites
0.00 %  
99+
0.00 %  
99+
Abundance In Earth's Crust
0.00 %  
99+
-  
Abundance In Oceans
-  
-  
Abundance In Humans
0.00 %  
24
0.00 %  
24
Uses
Uses & Benefits
  • Francium has no known uses as it has a half life of only 22 minutes.
  
  • Currently known uses of Mendelevium metal are limited to research purpose only.
  
Industrial Uses
-  
-  
Medical Uses
-  
-  
Other Uses
-  
-  
Biological Properties
  
  
Toxicity
-  
-  
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
27.00 °C  
99+
827.00 °C  
99+
Boiling Point
677.00 °C  
99+
0.00 °C  
99+
Appearance
  
  
Physical State
Solid  
Solid  
Color
-  
-  
Luster
-  
Metallic  
Hardness
  
  
Mohs Hardness
0.20  
27
-  
Brinell Hardness
119.00 MPa  
99+
350.00 MPa  
36
Vickers Hardness
300.00 MPa  
99+
0.00 MPa  
99+
Speed of Sound
2,440.00 m/s  
99+
2,680.00 m/s  
99+
Optical Properties
  
  
Refractive Index
1.70  
27
1.30  
99+
Reflectivity
72.00 %  
11
66.00 %  
17
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Fr  
Md  
Isotopes
  
  
Known Isotopes
33  
6
16  
23
Electronegativity
  
  
Pauling Electronegativity
0.70  
99+
1.30  
33
Sanderson Electronegativity
0.70  
99+
1.30  
25
Allred Rochow Electronegativity
0.86  
99+
1.20  
28
Mulliken-Jaffe Electronegativity
0.68  
99+
1.30  
33
Allen Electronegativity
0.67  
99+
1.30  
40
Electropositivity
  
  
Pauling Electropositivity
3.30  
1
2.70  
22
Ionization Energies
  
  
1st Energy Level
380.00 kJ/mol  
99+
635.00 kJ/mol  
99+
2nd Energy Level
392.80 kJ/mol  
99+
1,235.00 kJ/mol  
99+
3rd Energy Level
392.80 kJ/mol  
99+
2,470.00 kJ/mol  
99+
4th Energy Level
392.80 kJ/mol  
99+
3,840.00 kJ/mol  
99+
5th Energy Level
392.00 kJ/mol  
99+
6,350.00 kJ/mol  
36
6th Energy Level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
99+
7th Energy level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
99+
8th Energy Level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
99+
9th Energy Level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
99+
10th Energy Level
392.00 kJ/mol  
99+
6,350.00 kJ/mol  
99+
11th Energy Level
392.00 kJ/mol  
99+
6,400.00 kJ/mol  
99+
12th Energy Level
38,000.00 kJ/mol  
23
60,100.00 kJ/mol  
16
13th Energy Level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
37
14th Energy Level
380.00 kJ/mol  
99+
1,150.00 kJ/mol  
99+
15th Energy Level
67,700.00 kJ/mol  
32
63,500.00 kJ/mol  
37
16th Energy Level
39,200.00 kJ/mol  
99+
635.00 kJ/mol  
99+
17th Energy Level
392.00 kJ/mol  
99+
1,107.00 kJ/mol  
21
18th Energy Level
3,920.00 kJ/mol  
99+
6,350.00 kJ/mol  
39
19th Energy Level
392.80 kJ/mol  
99+
635.00 kJ/mol  
99+
20th Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
40
21st Energy Level
392.00 kJ/mol  
99+
6,350.00 kJ/mol  
13
22nd Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
34
23rd Energy Level
392.80 kJ/mol  
99+
6,350.00 kJ/mol  
13
24th Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
36
25th Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
38
26th Energy Level
392.80 kJ/mol  
99+
635.00 kJ/mol  
37
27th Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
39
28th Energy Level
380.00 kJ/mol  
99+
635.00 kJ/mol  
99+
29th Energy Level
392.00 kJ/mol  
99+
635.00 kJ/mol  
99+
30th Energy Level
677.00 kJ/mol  
31
635.00 kJ/mol  
40
Electrochemical Equivalent
8.32 g/amp-hr  
1
3.21 g/amp-hr  
13
Electron Work Function
4.07 eV  
33
3.89 eV  
37
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility  
Ionization, Radioactive Isotopes, Radioactivity  
Atomic
Atomic Number
87  
31
101  
17
Electron Configuration
[Rn] 7s1  
[Rn] 5f13 7s2  
Crystal Structure
Body Centered Cubic (BCC)  
Not Known  
Crystal Lattice
BCC-Crystal-Structure-.jpg#100  
Unknown-Crystal-Structure-of-Mendelevium.jpg#100  
Atom
  
  
Number of Protons
87  
31
101  
17
Number of Neutrons
136  
18
157  
8
Number of Electrons
87  
31
101  
17
Radius of an Atom
  
  
Atomic Radius
348.00 pm  
1
175.00 pm  
21
Covalent Radius
260.00 pm  
1
175.00 pm  
25
Van der Waals Radius
348.00 pm  
1
246.00 pm  
12
Atomic Weight
223.00 amu  
27
258.00 amu  
14
Atomic Volume
71.00 cm3/mol  
2
19.90 cm3/mol  
32
Adjacent Atomic Numbers
  
  
Previous Element
Polonium
  
Fermium
  
Next Element
Radium
  
Nobelium
  
Valence Electron Potential
8.00 (-eV)  
99+
63.70 (-eV)  
23
Lattice Constant
440.00 pm  
21
-  
Lattice Angles
-  
-  
Lattice C/A Ratio
1.56  
99+
1.58  
36
Mechanical
Density
  
  
Density At Room Temperature
1.87 g/cm3  
99+
10.30 g/cm3  
38
Density When Liquid (at m.p.)
1.87 g/cm3  
99+
10.30 g/cm3  
39
Tensile Strength
50.00 MPa  
38
80.00 MPa  
29
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
37
0.00 (Pa)  
37
Vapor Pressure at 2000 K
0.00 (Pa)  
24
0.00 (Pa)  
37
Elasticity properties
  
  
Shear Modulus
3.60 GPa  
99+
32.00 GPa  
24
Bulk Modulus
6.00 GPa  
99+
0.00 GPa  
99+
Young's Modulus
0.00 GPa  
99+
12.00 GPa  
99+
Poisson Ratio
0.44  
3
0.30  
14
Other Mechanical Properties
-  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
0.87  
99+
13.50  
29
Magnetic Ordering
Paramagnetic  
-  
Permeability
0.00 H/m  
13
0.00 H/m  
11
Susceptibility
0.00  
24
0.00  
24
Electrical Properties
  
  
Electrical Property
Poor Conductor  
-  
Resistivity
3.00 nΩ·m  
99+
0.63 nΩ·m  
99+
Electrical Conductivity
0.03 106/cm Ω  
99+
0.00 106/cm Ω  
99+
Electron Affinity
0.70 kJ/mol  
99+
50.00 kJ/mol  
26
Thermal
Specific Heat
0.15 J/(kg K)  
37
0.10 J/(kg K)  
99+
Molar Heat Capacity
27.00 J/mol·K  
29
27.00 J/mol·K  
29
Thermal Conductivity
15.00 W/m·K  
99+
0.00 W/m·K  
99+
Critical Temperature
300.00 K  
99+
1,100.00 K  
99+
Thermal Expansion
18.90 µm/(m·K)  
25
11.60 µm/(m·K)  
99+
Enthalpy
  
  
Enthalpy of Vaporization
67.00 kJ/mol  
99+
380.50 kJ/mol  
26
Enthalpy of Fusion
2.30 kJ/mol  
99+
-  
Enthalpy of Atomization
71.00 kJ/mol  
99+
410.80 kJ/mol  
25
Standard Molar Entropy
42.00 J/mol.K  
99+
37.40 J/mol.K  
99+
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