Symbol
Cf
Pa
Group Number
33
0
17
👆🏻
Period Number
77
2
7
👆🏻
Block
f block
f block
Element Family
Actinide
Actinide
CAS Number
74407137440133
7429905
54386242
👆🏻
Space Group Name
P63/mmc
I4/mmm
Space Group Number
194.00139.00
11
276
👆🏻
Interesting Facts
- Californium metal is very harmful and highly radioactive.
- Californium metal is the heaviest metal.
- Protactinium metal has 29 isotopes.
- Isotopes of Protactinium-231 used in nuclear weapon.
Sources
Made by Bombarding Curium with Helium Ions
Found in Uranium Ores, Mining, Ores of metals
History
Who Discovered
Lawrence Berkeley National Laboratory
William Crookes
Discovery
In 1950
In 1900
Abundance
Abundance In Universe
0.00 %0.00 %
0
0.11
👆🏻
Abundance In Sun
0.00 %0.00 %
0
0.1
👆🏻
Abundance In Meteorites
0.00 %-
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
-0.00 %
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Californium metal has a very strong neutron emitter. It is used as a metal detector.
-
It also used as an identifier to check Water and oil layers in oil wells.
- Currently known uses of Protactinium metal are limited to research purpose only.
Industrial Uses
Chemical Industry
-
Medical Uses
-
-
Other Uses
Alloys, Nuclear Research
-
Biological Properties
Toxicity
Toxic
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
900.00 °C1,568.00 °C
-38.83
3410
👆🏻
Boiling Point
1,470.00 °C4,027.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Silver
Luster
-
Metallic
Hardness
Mohs Hardness
3.005.00
0.2
8.5
👆🏻
Brinell Hardness
170.00 MPa125.00 MPa
0.14
3490
👆🏻
Vickers Hardness
1,800.00 MPa220.00 MPa
0
3920
👆🏻
Speed of Sound
2,260.00 m/s12,400.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.301.60
0.155
3.41
👆🏻
Reflectivity
63.00 %60.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Cf
Pa
Isotopes
Known Isotopes
2027
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.301.50
0
2.6
👆🏻
Sanderson Electronegativity
1.301.50
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.201.14
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.301.50
0.62
2.48
👆🏻
Allen Electronegativity
1.301.50
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.702.50
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
608.00 kJ/mol568.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,206.00 kJ/mol1,128.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
2,267.00 kJ/mol1,814.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,599.00 kJ/mol2,991.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,080.00 kJ/mol5,120.00 kJ/mol
392
97510
👆🏻
6th Energy Level
6,080.00 kJ/mol5,680.00 kJ/mol
1007
105800
👆🏻
7th Energy level
6,080.00 kJ/mol5,680.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
6,080.00 kJ/mol5,680.00 kJ/mol
730
125300
👆🏻
9th Energy Level
6,080.00 kJ/mol5,120.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
6,080.00 kJ/mol5,120.00 kJ/mol
392
144300
👆🏻
11th Energy Level
6,080.00 kJ/mol5,680.00 kJ/mol
392
169988
👆🏻
12th Energy Level
60,800.00 kJ/mol5,680.00 kJ/mol
0
189368
👆🏻
13th Energy Level
6,080.00 kJ/mol5,680.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
6,080.00 kJ/mol5,680.00 kJ/mol
380
86450
👆🏻
15th Energy Level
62,400.00 kJ/mol56,800.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
62,400.00 kJ/mol56,800.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
608.00 kJ/mol568.50 kJ/mol
375.7
122200
👆🏻
18th Energy Level
6,085.00 kJ/mol5,680.00 kJ/mol
0
134810
👆🏻
19th Energy Level
608.00 kJ/mol568.30 kJ/mol
375.7
148700
👆🏻
20th Energy Level
578.00 kJ/mol568.00 kJ/mol
0
171200
👆🏻
21st Energy Level
6,080.00 kJ/mol568.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
608.00 kJ/mol568.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
6,080.00 kJ/mol568.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
608.00 kJ/mol568.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
608.00 kJ/mol568.00 kJ/mol
0
121900
👆🏻
26th Energy Level
608.00 kJ/mol568.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
608.00 kJ/mol568.00 kJ/mol
0
133800
👆🏻
28th Energy Level
608.00 kJ/mol568.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
608.00 kJ/mol568.00 kJ/mol
0
148100
👆🏻
30th Energy Level
608.00 kJ/mol568.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
3.12 g/amp-hr1.72 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.70 eV5.89 eV
2.14
6
👆🏻
Other Chemical Properties
Corrosion, Ionization, Radioactive Isotopes, Radioactivity, Solubility
Ionization, Radioactive Isotopes, Radioactivity
Atomic Number
9891
3
117
👆🏻
Electron Configuration
[Rn] 5f10 7s2
[Rn] 5f2 6d1 7s2
Crystal Structure
Double Hexagonal Close Packed (DHCP)
Tetragonal (TETR)
Crystal Lattice
Atom
Number of Protons
9891
3
117
👆🏻
Number of Neutrons
153122
4
285
👆🏻
Number of Electrons
9891
3
117
👆🏻
Radius of an Atom
Atomic Radius
186.00 pm163.00 pm
0
348
👆🏻
Covalent Radius
186.00 pm200.00 pm
0
260
👆🏻
Van der Waals Radius
244.00 pm243.00 pm
0
348
👆🏻
Atomic Weight
251.00 amu231.04 amu
6.94
294
👆🏻
Atomic Volume
15.10 cm3/mol15.00 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
44.50 (-eV)92.00 (-eV)
0
392.42
👆🏻
Lattice Constant
338.00 pm392.50 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, 2 π/3
π/2, π/2, π/2
Lattice C/A Ratio
1.581.58
0.423
1.9
👆🏻
Density
Density At Room Temperature
15.10 g/cm315.37 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
15.10 g/cm315.37 g/cm3
0.512
41
👆🏻
Tensile Strength
50.00 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
29.00 GPa16.00 GPa
1.3
222
👆🏻
Bulk Modulus
40.00 GPa47.00 GPa
0
462
👆🏻
Young's Modulus
0.00 GPa47.00 GPa
0
528
👆🏻
Poisson Ratio
0.300.23
0.032
0.47
👆🏻
Other Mechanical Properties
Malleable, Sectile
-
Magnetic Characteristics
Specific Gravity
15.1015.37
0.53
4500
👆🏻
Magnetic Ordering
Paramagnetic
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
6.20 nΩ·m177.00 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.11 106/cm Ω0.05 106/cm Ω
0
0.63
👆🏻
Electron Affinity
97.00 kJ/mol53.03 kJ/mol
0
222.8
👆🏻
Specific Heat
0.10 J/(kg K)0.12 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
26.70 J/mol·K27.20 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
10.00 W/m·K47.00 W/m·K
0
429
👆🏻
Critical Temperature
900.00 K1,841.00 K
26.3
3695
👆🏻
Thermal Expansion
11.70 µm/(m·K)9.90 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
311.40 kJ/mol481.00 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
15.10 kJ/mol12.34 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
-481.90 kJ/mol
61.5
837
👆🏻
Standard Molar Entropy
50.00 J/mol.K198.10 J/mol.K
9.5
198.1
👆🏻