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Fermium vs Roentgenium

Fermium
Roentgenium
Roentgenium vs Fermium


Periodic Table
Symbol
Fm  
Rg  
Group Number
3  
15
11  
7
Period Number
7  
7  
Block
f block  
d block  
Element Family
Actinide  
-  
CAS Number
7440724  
19
54386242  
1
Space Group Name
-  
-  
Space Group Number
194.00  
7
194.00  
7
Facts
Interesting Facts
  • Fermium metal is highly radioactive in nature.
  • Fermium is synthetically produced metal.
  
Roentgenium is a highly unstable synthetic element.  
Sources
Bombarding Pu-239 with Neutrons  
Synthetically Produced  
History
  
  
Who Discovered
Lawrence Berkeley National Laboratory  
Gesellschaft für Schwerionenforschung  
Discovery
In 1952  
In 1994  
Abundance
  
  
Abundance In Universe
0.00 %  
35
0.00 %  
40
Abundance In Sun
0.00 %  
30
-  
Abundance In Meteorites
0.00 %  
99+
-  
Abundance In Earth's Crust
0.00 %  
99+
-  
Abundance In Oceans
-  
-  
Abundance In Humans
-  
-  
Uses
Uses & Benefits
  • Currently known uses of Fermium metal are limited to research purpose only.
  
  • Currently known uses of Roentgenium metal are limited to research purpose only.
  
Industrial Uses
-  
-  
Medical Uses
-  
-  
Other Uses
-  
Research Purposes  
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
1,527.00 °C  
26
-  
Boiling Point
0.00 °C  
99+
2,800.00 °C  
38
Appearance
  
  
Physical State
Solid  
Solid  
Color
-  
Silver  
Luster
-  
Unknown Luster  
Hardness
  
  
Mohs Hardness
6.00  
6
-  
Brinell Hardness
500.00 MPa  
28
700.00 MPa  
17
Vickers Hardness
600.00 MPa  
28
450.00 MPa  
38
Speed of Sound
2,500.00 m/s  
99+
3,430.00 m/s  
32
Optical Properties
  
  
Refractive Index
1.30  
99+
1.30  
99+
Reflectivity
59.00 %  
24
64.00 %  
19
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Fm  
Rg  
Isotopes
  
  
Known Isotopes
18  
21
1  
34
Electronegativity
  
  
Pauling Electronegativity
1.30  
33
0.00  
99+
Sanderson Electronegativity
1.30  
25
1.90  
13
Allred Rochow Electronegativity
1.20  
28
1.30  
25
Mulliken-Jaffe Electronegativity
1.30  
33
0.90  
99+
Allen Electronegativity
1.30  
40
0.80  
99+
Electropositivity
  
  
Pauling Electropositivity
2.70  
22
2.20  
39
Ionization Energies
  
  
1st Energy Level
627.00 kJ/mol  
99+
1,022.70 kJ/mol  
3
2nd Energy Level
1,225.00 kJ/mol  
99+
2,074.40 kJ/mol  
10
3rd Energy Level
2,363.00 kJ/mol  
99+
3,077.90 kJ/mol  
24
4th Energy Level
3,792.00 kJ/mol  
99+
4,052.40 kJ/mol  
99+
5th Energy Level
6,270.00 kJ/mol  
39
5,306.70 kJ/mol  
99+
6th Energy Level
6,270.00 kJ/mol  
99+
11,100.00 kJ/mol  
10
7th Energy level
6,270.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
8th Energy Level
6,270.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
9th Energy Level
7,040.00 kJ/mol  
33
5,650.00 kJ/mol  
99+
10th Energy Level
6,270.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
11th Energy Level
6,270.00 kJ/mol  
99+
8,300.00 kJ/mol  
24
12th Energy Level
62,700.00 kJ/mol  
10
8,300.00 kJ/mol  
99+
13th Energy Level
6,270.00 kJ/mol  
38
8,700.00 kJ/mol  
16
14th Energy Level
6,270.00 kJ/mol  
27
8,300.00 kJ/mol  
16
15th Energy Level
62,700.00 kJ/mol  
38
87,000.00 kJ/mol  
9
16th Energy Level
62,700.00 kJ/mol  
28
83,000.00 kJ/mol  
11
17th Energy Level
627.00 kJ/mol  
99+
830.80 kJ/mol  
30
18th Energy Level
6,270.00 kJ/mol  
40
8,300.00 kJ/mol  
19
19th Energy Level
994.80 kJ/mol  
21
580.00 kJ/mol  
99+
20th Energy Level
627.00 kJ/mol  
99+
580.00 kJ/mol  
99+
21st Energy Level
627.00 kJ/mol  
99+
5,800.00 kJ/mol  
21
22nd Energy Level
345.00 kJ/mol  
99+
580.00 kJ/mol  
99+
23rd Energy Level
6,270.00 kJ/mol  
14
5,800.00 kJ/mol  
21
24th Energy Level
627.60 kJ/mol  
38
538.70 kJ/mol  
99+
25th Energy Level
627.00 kJ/mol  
40
0.00 kJ/mol  
99+
26th Energy Level
627.60 kJ/mol  
39
580.00 kJ/mol  
99+
27th Energy Level
627.60 kJ/mol  
99+
580.00 kJ/mol  
99+
28th Energy Level
627.60 kJ/mol  
99+
880.00 kJ/mol  
8
29th Energy Level
627.60 kJ/mol  
99+
580.00 kJ/mol  
99+
30th Energy Level
627.60 kJ/mol  
99+
0.00 kJ/mol  
99+
Electrochemical Equivalent
3.20 g/amp-hr  
15
3.10 g/amp-hr  
18
Electron Work Function
4.47 eV  
21
4.90 eV  
12
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity  
-  
Atomic
Atomic Number
100  
18
111  
7
Electron Configuration
[Rn] 5f12 7s2  
[Rn] 5f14 6d9 7s2  
Crystal Structure
Not Known  
Body Centered Cubic (BCC)  
Crystal Lattice
Unknown-Crystal-Structure-of-Fermium.jpg#100  
BCC-Crystal-Structure-.jpg#100  
Atom
  
  
Number of Protons
100  
18
111  
7
Number of Neutrons
157  
8
161  
4
Number of Electrons
100  
18
111  
7
Radius of an Atom
  
  
Atomic Radius
180.00 pm  
16
200.00 pm  
7
Covalent Radius
180.00 pm  
23
126.00 pm  
99+
Van der Waals Radius
245.00 pm  
13
280.00 pm  
6
Atomic Weight
257.00 amu  
15
281.00 amu  
6
Atomic Volume
18.00 cm3/mol  
99+
28.70 cm3/mol  
12
Adjacent Atomic Numbers
  
  
Previous Element
Einsteinium
  
Darmstadtium
  
Next Element
Mendelevium
  
Copernicium
  
Valence Electron Potential
0.00 (-eV)  
99+
11.90 (-eV)  
99+
Lattice Constant
350.00 pm  
99+
0.00 pm  
99+
Lattice Angles
-  
-  
Lattice C/A Ratio
1.63  
13
1.90  
1
Mechanical
Density
  
  
Density At Room Temperature
9.70 g/cm3  
99+
28.70 g/cm3  
6
Density When Liquid (at m.p.)
9.70 g/cm3  
99+
28.70 g/cm3  
7
Tensile Strength
0.10 MPa  
99+
65.00 MPa  
33
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
22
0.00 (Pa)  
37
Vapor Pressure at 2000 K
0.00 (Pa)  
30
0.00 (Pa)  
99+
Elasticity properties
  
  
Shear Modulus
30.00 GPa  
27
26.00 GPa  
36
Bulk Modulus
50.00 GPa  
24
0.00 GPa  
99+
Young's Modulus
0.00 GPa  
99+
12.70 GPa  
99+
Poisson Ratio
0.35  
9
0.30  
14
Other Mechanical Properties
-  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
9.70  
99+
28.70  
8
Magnetic Ordering
-  
-  
Permeability
0.00 H/m  
16
0.00 H/m  
12
Susceptibility
0.00  
24
0.00  
24
Electrical Properties
  
  
Electrical Property
-  
-  
Resistivity
7.90 nΩ·m  
99+
0.20 nΩ·m  
99+
Electrical Conductivity
0.00 106/cm Ω  
99+
0.00 106/cm Ω  
99+
Electron Affinity
0.00 kJ/mol  
99+
50.00 kJ/mol  
26
Thermal
Specific Heat
0.10 J/(kg K)  
99+
0.13 J/(kg K)  
40
Molar Heat Capacity
27.00 J/mol·K  
29
23.70 J/mol·K  
99+
Thermal Conductivity
0.00 W/m·K  
99+
0.10 W/m·K  
99+
Critical Temperature
1,323.00 K  
99+
1,100.00 K  
99+
Thermal Expansion
11.00 µm/(m·K)  
99+
12.60 µm/(m·K)  
40
Enthalpy
  
  
Enthalpy of Vaporization
319.20 kJ/mol  
99+
580.00 kJ/mol  
12
Enthalpy of Fusion
13.30 kJ/mol  
30
-  
Enthalpy of Atomization
-  
580.00 kJ/mol  
14
Standard Molar Entropy
50.00 J/mol.K  
99+
57.00 J/mol.K  
30
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