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Erbium vs Roentgenium

Erbium
Roentgenium
Roentgenium vs Erbium


Periodic Table
Symbol
Er  
Rg  
Group Number
3  
15
11  
7
Period Number
6  
7  
Block
f block  
d block  
Element Family
Lanthanide  
-  
CAS Number
7440520  
35
54386242  
1
Space Group Name
P63/mmc  
-  
Space Group Number
194.00  
7
194.00  
7
Facts
Interesting Facts
  • Erbium metal is used as alloyed with Vanadium to make it softer.
  • Recent studies shows that it is helpful for metabolism.
  
Roentgenium is a highly unstable synthetic element.  
Sources
Mining  
Synthetically Produced  
History
  
  
Who Discovered
Carl Gustaf Mosander  
Gesellschaft für Schwerionenforschung  
Discovery
In 1842  
In 1994  
Abundance
  
  
Abundance In Universe
0.00 %  
23
0.00 %  
40
Abundance In Sun
0.00 %  
26
-  
Abundance In Meteorites
0.00 %  
36
-  
Abundance In Earth's Crust
0.00 %  
32
-  
Abundance In Oceans
0.00 %  
36
-  
Abundance In Humans
0.00 %  
24
-  
Uses
Uses & Benefits
  • It has a tendency to get tarnished in the open air, but when alloyed with elements like erbium, vanadium, its hardness levels decreases.
  • Its compounds like Erbium oxide is used in safety glasses of welders and metal workers.
  
  • Currently known uses of Roentgenium metal are limited to research purpose only.
  
Industrial Uses
Chemical Industry  
-  
Medical Uses
-  
-  
Other Uses
Alloys  
Research Purposes  
Biological Properties
  
  
Toxicity
Mildly Toxic  
-  
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
1,522.00 °C  
28
-  
Boiling Point
2,510.00 °C  
99+
2,800.00 °C  
38
Appearance
  
  
Physical State
Solid  
Solid  
Color
Silvery White  
Silver  
Luster
Lustrous  
Unknown Luster  
Hardness
  
  
Mohs Hardness
1.00  
22
-  
Brinell Hardness
814.00 MPa  
12
700.00 MPa  
17
Vickers Hardness
589.00 MPa  
30
450.00 MPa  
38
Speed of Sound
2,830.00 m/s  
99+
3,430.00 m/s  
32
Optical Properties
  
  
Refractive Index
1.76  
24
1.30  
99+
Reflectivity
36.00 %  
33
64.00 %  
19
Allotropes
No  
No  
α Allotropes
-  
-  
β Allotropes
-  
-  
γ Allotropes
-  
-  
Chemical
Chemical Formula
Er  
Rg  
Isotopes
  
  
Known Isotopes
31  
8
1  
34
Electronegativity
  
  
Pauling Electronegativity
1.24  
37
0.00  
99+
Sanderson Electronegativity
1.24  
29
1.90  
13
Allred Rochow Electronegativity
1.11  
30
1.30  
25
Mulliken-Jaffe Electronegativity
1.24  
36
0.90  
99+
Allen Electronegativity
1.24  
99+
0.80  
99+
Electropositivity
  
  
Pauling Electropositivity
2.76  
18
2.20  
39
Ionization Energies
  
  
1st Energy Level
589.30 kJ/mol  
99+
1,022.70 kJ/mol  
3
2nd Energy Level
1,150.00 kJ/mol  
99+
2,074.40 kJ/mol  
10
3rd Energy Level
2,194.00 kJ/mol  
99+
3,077.90 kJ/mol  
24
4th Energy Level
4,120.00 kJ/mol  
99+
4,052.40 kJ/mol  
99+
5th Energy Level
5,897.00 kJ/mol  
99+
5,306.70 kJ/mol  
99+
6th Energy Level
5,897.00 kJ/mol  
99+
11,100.00 kJ/mol  
10
7th Energy level
5,890.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
8th Energy Level
5,890.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
9th Energy Level
4,240.00 kJ/mol  
99+
5,650.00 kJ/mol  
99+
10th Energy Level
5,890.00 kJ/mol  
99+
5,800.00 kJ/mol  
99+
11th Energy Level
5,890.00 kJ/mol  
99+
8,300.00 kJ/mol  
24
12th Energy Level
5,890.00 kJ/mol  
99+
8,300.00 kJ/mol  
99+
13th Energy Level
5,890.00 kJ/mol  
99+
8,700.00 kJ/mol  
16
14th Energy Level
5,890.00 kJ/mol  
37
8,300.00 kJ/mol  
16
15th Energy Level
58,900.00 kJ/mol  
99+
87,000.00 kJ/mol  
9
16th Energy Level
58,900.00 kJ/mol  
38
83,000.00 kJ/mol  
11
17th Energy Level
589.30 kJ/mol  
99+
830.80 kJ/mol  
30
18th Energy Level
5,890.00 kJ/mol  
99+
8,300.00 kJ/mol  
19
19th Energy Level
589.30 kJ/mol  
99+
580.00 kJ/mol  
99+
20th Energy Level
589.00 kJ/mol  
99+
580.00 kJ/mol  
99+
21st Energy Level
5,897.00 kJ/mol  
19
5,800.00 kJ/mol  
21
22nd Energy Level
589.00 kJ/mol  
99+
580.00 kJ/mol  
99+
23rd Energy Level
589.30 kJ/mol  
99+
5,800.00 kJ/mol  
21
24th Energy Level
589.30 kJ/mol  
99+
538.70 kJ/mol  
99+
25th Energy Level
589.00 kJ/mol  
99+
0.00 kJ/mol  
99+
26th Energy Level
589.30 kJ/mol  
99+
580.00 kJ/mol  
99+
27th Energy Level
589.30 kJ/mol  
99+
580.00 kJ/mol  
99+
28th Energy Level
589.30 kJ/mol  
99+
880.00 kJ/mol  
8
29th Energy Level
589.30 kJ/mol  
99+
580.00 kJ/mol  
99+
30th Energy Level
589.70 kJ/mol  
99+
0.00 kJ/mol  
99+
Electrochemical Equivalent
2.08 g/amp-hr  
32
3.10 g/amp-hr  
18
Electron Work Function
5.93 eV  
2
4.90 eV  
12
Other Chemical Properties
Ionization, Radioactive Isotopes, Solubility  
-  
Atomic
Atomic Number
68  
99+
111  
7
Electron Configuration
[Xe] 4f12 6s2  
[Rn] 5f14 6d9 7s2  
Crystal Structure
Hexagonal Close Packed (HCP)  
Body Centered Cubic (BCC)  
Crystal Lattice
HCP-Crystal-Structure-of-Erbium.jpg#100  
BCC-Crystal-Structure-.jpg#100  
Atom
  
  
Number of Protons
68  
99+
111  
7
Number of Neutrons
99  
34
161  
4
Number of Electrons
68  
99+
111  
7
Radius of an Atom
  
  
Atomic Radius
176.00 pm  
20
200.00 pm  
7
Covalent Radius
189.00 pm  
19
126.00 pm  
99+
Van der Waals Radius
0.00 pm  
99+
280.00 pm  
6
Atomic Weight
167.26 amu  
99+
281.00 amu  
6
Atomic Volume
18.40 cm3/mol  
37
28.70 cm3/mol  
12
Adjacent Atomic Numbers
  
  
Previous Element
Holmium
  
Darmstadtium
  
Next Element
Thulium
  
Copernicium
  
Valence Electron Potential
49.00 (-eV)  
30
11.90 (-eV)  
99+
Lattice Constant
355.88 pm  
99+
0.00 pm  
99+
Lattice Angles
π/2, π/2, 2 π/3  
-  
Lattice C/A Ratio
1.57  
40
1.90  
1
Mechanical
Density
  
  
Density At Room Temperature
9.07 g/cm3  
99+
28.70 g/cm3  
6
Density When Liquid (at m.p.)
8.86 g/cm3  
99+
28.70 g/cm3  
7
Tensile Strength
350.00 MPa  
12
65.00 MPa  
33
Viscosity
0.00  
25
0.00  
25
Vapor Pressure
  
  
Vapor Pressure at 1000 K
0.00 (Pa)  
21
0.00 (Pa)  
37
Vapor Pressure at 2000 K
0.00 (Pa)  
30
0.00 (Pa)  
99+
Elasticity properties
  
  
Shear Modulus
28.30 GPa  
31
26.00 GPa  
36
Bulk Modulus
44.40 GPa  
31
0.00 GPa  
99+
Young's Modulus
69.90 GPa  
31
12.70 GPa  
99+
Poisson Ratio
0.24  
28
0.30  
14
Other Mechanical Properties
Malleable  
-  
Magnetic
Magnetic Characteristics
  
  
Specific Gravity
9.07  
99+
28.70  
8
Magnetic Ordering
Paramagnetic  
-  
Permeability
0.00 H/m  
17
0.00 H/m  
12
Susceptibility
0.00  
11
0.00  
24
Electrical Properties
  
  
Electrical Property
Conductor  
-  
Resistivity
0.86 nΩ·m  
99+
0.20 nΩ·m  
99+
Electrical Conductivity
0.01 106/cm Ω  
99+
0.00 106/cm Ω  
99+
Electron Affinity
50.00 kJ/mol  
26
50.00 kJ/mol  
26
Thermal
Specific Heat
0.17 J/(kg K)  
35
0.13 J/(kg K)  
40
Molar Heat Capacity
28.12 J/mol·K  
14
23.70 J/mol·K  
99+
Thermal Conductivity
14.50 W/m·K  
99+
0.10 W/m·K  
99+
Critical Temperature
1,802.00 K  
30
1,100.00 K  
99+
Thermal Expansion
12.20 µm/(m·K)  
99+
12.60 µm/(m·K)  
40
Enthalpy
  
  
Enthalpy of Vaporization
261.00 kJ/mol  
99+
580.00 kJ/mol  
12
Enthalpy of Fusion
17.20 kJ/mol  
15
-  
Enthalpy of Atomization
314.00 kJ/mol  
99+
580.00 kJ/mol  
14
Standard Molar Entropy
73.10 J/mol.K  
11
57.00 J/mol.K  
30
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