Symbol
Np
Cf
Group Number
33
0
17
👆🏻
Period Number
77
2
7
👆🏻
Block
f block
f block
Element Family
Actinide
Actinide
CAS Number
74399987440713
7429905
54386242
👆🏻
Space Group Name
Pnma
P63/mmc
Space Group Number
62.00194.00
11
276
👆🏻
Interesting Facts
Neptunium was the first transuranium element to be discovered.
- Californium metal is very harmful and highly radioactive.
- Californium metal is the heaviest metal.
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals
Made by Bombarding Curium with Helium Ions
History
Who Discovered
Edwin McMillan and Philip H. Abelson
Lawrence Berkeley National Laboratory
Discovery
In 1940
In 1950
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 %0.00 %
0
22
👆🏻
Abundance In Earth's Crust
0.00 %0.00 %
1E-37
8.1
👆🏻
Abundance In Oceans
--
0
1.1
👆🏻
Abundance In Humans
0.00 %0.00 %
0
1.4
👆🏻
Uses & Benefits
- Currently known uses of Neptunium metal are limited to research purpose only.
-
Neptunium’s isotope neptunium-237 is used as a neutron detectors.
- 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.
Industrial Uses
-
Chemical Industry
Medical Uses
-
-
Other Uses
Alloys, Nuclear Research, Research Purposes
Alloys, Nuclear Research
Biological Properties
Toxicity
Toxic
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
640.00 °C900.00 °C
-38.83
3410
👆🏻
Boiling Point
3,902.00 °C1,470.00 °C
0
5660
👆🏻
Appearance
Physical State
Solid
Solid
Color
Silver
Silver
Luster
Metallic
-
Hardness
Mohs Hardness
6.003.00
0.2
8.5
👆🏻
Brinell Hardness
622.00 MPa170.00 MPa
0.14
3490
👆🏻
Vickers Hardness
640.00 MPa1,800.00 MPa
0
3920
👆🏻
Speed of Sound
2,260.00 m/s2,260.00 m/s
818
16200
👆🏻
Optical Properties
Refractive Index
1.301.30
0.155
3.41
👆🏻
Reflectivity
64.00 %63.00 %
5
97
👆🏻
Allotropes
✔
✘
✔
✘
α Allotropes
-
-
β Allotropes
-
-
γ Allotropes
-
-
Chemical Formula
Np
Cf
Isotopes
Known Isotopes
2020
0
38
👆🏻
Electronegativity
Pauling Electronegativity
1.361.30
0
2.6
👆🏻
Sanderson Electronegativity
1.361.30
0.22
2.56
👆🏻
Allred Rochow Electronegativity
1.221.20
0.86
1.9
👆🏻
Mulliken-Jaffe Electronegativity
1.361.30
0.62
2.48
👆🏻
Allen Electronegativity
1.361.30
0.659
2.7
👆🏻
Electropositivity
Pauling Electropositivity
2.642.70
1.46
3.3
👆🏻
Ionization Energies
1st Energy Level
604.50 kJ/mol608.00 kJ/mol
375.7
26130
👆🏻
2nd Energy Level
1,128.00 kJ/mol1,206.00 kJ/mol
392.8
28750
👆🏻
3rd Energy Level
1,997.00 kJ/mol2,267.00 kJ/mol
392.8
34230
👆🏻
4th Energy Level
3,242.00 kJ/mol3,599.00 kJ/mol
375.7
37066
👆🏻
5th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
392
97510
👆🏻
6th Energy Level
5,785.00 kJ/mol6,080.00 kJ/mol
1007
105800
👆🏻
7th Energy level
6,040.00 kJ/mol6,080.00 kJ/mol
1007
114300
👆🏻
8th Energy Level
6,040.00 kJ/mol6,080.00 kJ/mol
730
125300
👆🏻
9th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
1007
134700
👆🏻
10th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
392
144300
👆🏻
11th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
392
169988
👆🏻
12th Energy Level
61,800.00 kJ/mol60,800.00 kJ/mol
0
189368
👆🏻
13th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
1007
76015
👆🏻
14th Energy Level
6,180.00 kJ/mol6,080.00 kJ/mol
380
86450
👆🏻
15th Energy Level
60,600.00 kJ/mol62,400.00 kJ/mol
33000
100700
👆🏻
16th Energy Level
60,420.00 kJ/mol62,400.00 kJ/mol
375.7
109480
👆🏻
17th Energy Level
604.00 kJ/mol608.00 kJ/mol
375.7
122200
👆🏻
18th Energy Level
6,040.00 kJ/mol6,085.00 kJ/mol
0
134810
👆🏻
19th Energy Level
604.50 kJ/mol608.00 kJ/mol
375.7
148700
👆🏻
20th Energy Level
604.00 kJ/mol578.00 kJ/mol
0
171200
👆🏻
21st Energy Level
6,040.00 kJ/mol6,080.00 kJ/mol
375.7
179100
👆🏻
22nd Energy Level
604.00 kJ/mol608.00 kJ/mol
330
184900
👆🏻
23rd Energy Level
6,040.00 kJ/mol6,080.00 kJ/mol
357.6
198800
👆🏻
24th Energy Level
604.50 kJ/mol608.00 kJ/mol
297.3
195200
👆🏻
25th Energy Level
604.00 kJ/mol608.00 kJ/mol
0
121900
👆🏻
26th Energy Level
604.00 kJ/mol608.00 kJ/mol
357.6
127700
👆🏻
27th Energy Level
604.00 kJ/mol608.00 kJ/mol
0
133800
👆🏻
28th Energy Level
604.00 kJ/mol608.00 kJ/mol
297.3
139800
👆🏻
29th Energy Level
604.00 kJ/mol608.00 kJ/mol
0
148100
👆🏻
30th Energy Level
604.00 kJ/mol608.00 kJ/mol
0
154500
👆🏻
Electrochemical Equivalent
1.77 g/amp-hr3.12 g/amp-hr
0.16812
8.3209
👆🏻
Electron Work Function
4.90 eV4.70 eV
2.14
6
👆🏻
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Corrosion, Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Number
9398
3
117
👆🏻
Electron Configuration
[Rn] 5f4 6d1 7s2
[Rn] 5f10 7s2
Crystal Structure
Orthorhombic (ORTH)
Double Hexagonal Close Packed (DHCP)
Crystal Lattice
Atom
Number of Protons
9398
3
117
👆🏻
Number of Neutrons
144153
4
285
👆🏻
Number of Electrons
9398
3
117
👆🏻
Radius of an Atom
Atomic Radius
155.00 pm186.00 pm
0
348
👆🏻
Covalent Radius
190.00 pm186.00 pm
0
260
👆🏻
Van der Waals Radius
221.00 pm244.00 pm
0
348
👆🏻
Atomic Weight
237.00 amu251.00 amu
6.94
294
👆🏻
Atomic Volume
11.62 cm3/mol15.10 cm3/mol
1.39
71.07
👆🏻
Adjacent Atomic Numbers
Previous Element
Next Element
Valence Electron Potential
96.00 (-eV)44.50 (-eV)
0
392.42
👆🏻
Lattice Constant
666.30 pm338.00 pm
0
891.25
👆🏻
Lattice Angles
π/2, π/2, π/2
π/2, π/2, 2 π/3
Lattice C/A Ratio
1.431.58
0.423
1.9
👆🏻
Density
Density At Room Temperature
19.38 g/cm315.10 g/cm3
0.534
40.7
👆🏻
Density When Liquid (at m.p.)
20.25 g/cm315.10 g/cm3
0.512
41
👆🏻
Tensile Strength
125.00 MPa50.00 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
0.11 (Pa)0.00 (Pa)
0
774
👆🏻
Elasticity properties
Shear Modulus
5.60 GPa29.00 GPa
1.3
222
👆🏻
Bulk Modulus
180.00 GPa40.00 GPa
0
462
👆🏻
Young's Modulus
46.00 GPa0.00 GPa
0
528
👆🏻
Poisson Ratio
0.260.30
0.032
0.47
👆🏻
Other Mechanical Properties
Ductile
Malleable, Sectile
Magnetic Characteristics
Specific Gravity
20.2515.10
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
1.22 nΩ·m6.20 nΩ·m
0.1
961
👆🏻
Electrical Conductivity
0.01 106/cm Ω0.11 106/cm Ω
0
0.63
👆🏻
Electron Affinity
118.60 kJ/mol97.00 kJ/mol
0
222.8
👆🏻
Specific Heat
0.12 J/(kg K)0.10 J/(kg K)
0.1
3.6
👆🏻
Molar Heat Capacity
29.46 J/mol·K26.70 J/mol·K
13.1
62.7
👆🏻
Thermal Conductivity
6.30 W/m·K10.00 W/m·K
0
429
👆🏻
Critical Temperature
913.00 K900.00 K
26.3
3695
👆🏻
Thermal Expansion
13.30 µm/(m·K)11.70 µm/(m·K)
4.5
97
👆🏻
Enthalpy
Enthalpy of Vaporization
336.00 kJ/mol311.40 kJ/mol
7.32
799.1
👆🏻
Enthalpy of Fusion
3.20 kJ/mol15.10 kJ/mol
2.1
35.23
👆🏻
Enthalpy of Atomization
275.30 kJ/mol-
61.5
837
👆🏻
Standard Molar Entropy
64.00 J/mol.K50.00 J/mol.K
9.5
198.1
👆🏻