Symbol
Rg
Pa
Group Number
113
0
17
👆🏻
Period Number
77
2
7
👆🏻
Block
d block
f block
Element Family
-
Actinide
CAS Number
543862427440133
7429905
54386242
👆🏻
Space Group Name
-
I4/mmm
Space Group Number
194.00139.00
11
276
👆🏻
Interesting Facts
Roentgenium is a highly unstable synthetic element.
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
Sources
Synthetically Produced
Found in Uranium Ores, Mining, Ores of metals
History
Who Discovered
Gesellschaft für Schwerionenforschung
William Crookes
Discovery
In 1994
In 1900
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
-0.00 %
0
0.1
👆🏻
Abundance In Meteorites
--
0
22
👆🏻
Abundance In Earth's Crust
-0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
-0.00 %
0
1.1
👆🏻
Abundance In Humans
-0.00 %
0
1.4
👆🏻
Uses & Benefits
- Currently known uses of Roentgenium metal are limited to research purpose only.
- Currently known uses of Protactinium metal are limited to research purpose only.
Industrial Uses
-
-
Medical Uses
-
-
Other Uses
Research Purposes
-
Biological Properties
Toxicity
-
Highly Toxic
Present in Human Body
✔
✘
✔
✘
In Blood
0.00 Blood/mg dm-30.00 Blood/mg dm-3
0
1970
👆🏻
In Bone
0.00 p.p.m.0.00 p.p.m.
0
170000
👆🏻
Melting Point
-1,568.00 °C
-38.83
3410
👆🏻
Boiling Point
2,800.00 °C4,027.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Silver
Luster
Unknown Luster
Metallic
Hardness
Mohs Hardness
-5.00
0.2
8.5
👆🏻
Brinell Hardness
700.00 MPa125.00 MPa
0.14
3490
👆🏻
Vickers Hardness
450.00 MPa220.00 MPa
0
3920
👆🏻
Speed of Sound
3,430.00 m/s12,400.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.301.60
0.155
3.41
👆🏻
Reflectivity
64.00 %60.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Rg
Pa
Isotopes
Known Isotopes
127
0
38
👆🏻
Electronegativity
Pauling Electronegativity
0.001.50
0
2.6
👆🏻
Sanderson Electronegativity
1.901.50
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.301.14
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
0.901.50
0.62
2.48
👆🏻
Allen Electronegativity
0.801.50
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.202.50
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
1,022.70 kJ/mol568.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
2,074.40 kJ/mol1,128.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
3,077.90 kJ/mol1,814.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
4,052.40 kJ/mol2,991.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
5,306.70 kJ/mol5,120.00 kJ/mol
392
97510
👆🏻
6th Energy Level
11,100.00 kJ/mol5,680.00 kJ/mol
1007
105800
👆🏻
7th Energy level
5,800.00 kJ/mol5,680.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
5,800.00 kJ/mol5,680.00 kJ/mol
730
125300
👆🏻
9th Energy Level
5,650.00 kJ/mol5,120.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
5,800.00 kJ/mol5,120.00 kJ/mol
392
144300
👆🏻
11th Energy Level
8,300.00 kJ/mol5,680.00 kJ/mol
392
169988
👆🏻
12th Energy Level
8,300.00 kJ/mol5,680.00 kJ/mol
0
189368
👆🏻
13th Energy Level
8,700.00 kJ/mol5,680.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
8,300.00 kJ/mol5,680.00 kJ/mol
380
86450
👆🏻
15th Energy Level
87,000.00 kJ/mol56,800.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
83,000.00 kJ/mol56,800.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
830.80 kJ/mol568.50 kJ/mol
375.7
122200
👆🏻
18th Energy Level
8,300.00 kJ/mol5,680.00 kJ/mol
0
134810
👆🏻
19th Energy Level
580.00 kJ/mol568.30 kJ/mol
375.7
148700
👆🏻
20th Energy Level
580.00 kJ/mol568.00 kJ/mol
0
171200
👆🏻
21st Energy Level
5,800.00 kJ/mol568.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
580.00 kJ/mol568.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
5,800.00 kJ/mol568.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
538.70 kJ/mol568.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
0.00 kJ/mol568.00 kJ/mol
0
121900
👆🏻
26th Energy Level
580.00 kJ/mol568.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
580.00 kJ/mol568.00 kJ/mol
0
133800
👆🏻
28th Energy Level
880.00 kJ/mol568.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
580.00 kJ/mol568.00 kJ/mol
0
148100
👆🏻
30th Energy Level
0.00 kJ/mol568.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
3.10 g/amp-hr1.72 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.90 eV5.89 eV
2.14
6
👆🏻
Other Chemical Properties
-
Ionization, Radioactive Isotopes, Radioactivity
Atomic Number
11191
3
117
👆🏻
Electron Configuration
[Rn] 5f14 6d9 7s2
[Rn] 5f2 6d1 7s2
Crystal Structure
Body Centered Cubic (BCC)
Tetragonal (TETR)
Crystal Lattice
Atom
Number of Protons
11191
3
117
👆🏻
Number of Neutrons
161122
4
285
👆🏻
Number of Electrons
11191
3
117
👆🏻
Radius of an Atom
Atomic Radius
200.00 pm163.00 pm
0
348
👆🏻
Covalent Radius
126.00 pm200.00 pm
0
260
👆🏻
Van der Waals Radius
280.00 pm243.00 pm
0
348
👆🏻
Atomic Weight
281.00 amu231.04 amu
6.94
294
👆🏻
Atomic Volume
28.70 cm3/mol15.00 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
11.90 (-eV)92.00 (-eV)
0
392.42
👆🏻
Lattice Constant
0.00 pm392.50 pm
0
891.25
👆🏻
Lattice Angles
-
π/2, π/2, π/2
Lattice C/A Ratio
1.901.58
0.423
1.9
👆🏻
Density
Density At Room Temperature
28.70 g/cm315.37 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
28.70 g/cm315.37 g/cm3
0.512
41
👆🏻
Tensile Strength
65.00 MPa80.00 MPa
0.1
11000
👆🏻
Viscosity
0.000.00
1.5E-05
0.0035
👆🏻
Vapor Pressure
Vapor Pressure at 1000 K
0.00 (Pa)0.00 (Pa)
0
121
👆🏻
Vapor Pressure at 2000 K
0.00 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
26.00 GPa16.00 GPa
1.3
222
👆🏻
Bulk Modulus
0.00 GPa47.00 GPa
0
462
👆🏻
Young's Modulus
12.70 GPa47.00 GPa
0
528
👆🏻
Poisson Ratio
0.300.23
0.032
0.47
👆🏻
Other Mechanical Properties
-
-
Magnetic Characteristics
Specific Gravity
28.7015.37
0.53
4500
👆🏻
Magnetic Ordering
-
Paramagnetic
Permeability
0.00 H/m0.00 H/m
1.25643E-06
0.0063
👆🏻
Susceptibility
0.000.00
-0.000166
200000
👆🏻
Electrical Properties
Electrical Property
-
Conductor
Resistivity
0.20 nΩ·m177.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.00 106/cm Ω0.05 106/cm Ω
0
0.63
👆🏻
Electron Affinity
50.00 kJ/mol53.03 kJ/mol
0
222.8
👆🏻
Specific Heat
0.13 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
23.70 J/mol·K27.20 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
0.10 W/m·K47.00 W/m·K
0
429
👆🏻
Critical Temperature
1,100.00 K1,841.00 K
26.3
3695
👆🏻
Thermal Expansion
12.60 µm/(m·K)9.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
580.00 kJ/mol481.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
-12.34 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
580.00 kJ/mol481.90 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
57.00 J/mol.K198.10 J/mol.K
9.5
198.1
👆🏻