Neptunium vs Strontium
Periodic Table
Symbol
Np
Sr
Group Number
Not Available
2
16
Period Number
7
5
Block
f block
s block
Element Family
Actinide
Alkaline Earth
CAS Number
7439998
99+
7440246
99+
Space Group Name
Pnma
Fm_ 3m
Space Group Number
62.00
11
225.00
2
Facts
Interesting Facts
Not Available
- Strontium element is softer than Calcium.
- Silvery Strontium turns yellow, if exposed to air.
Sources
Made by Bombarding Uranium with Neutrons, Ores of metals
Found in Minerals, Mining, Ores of Minerals
History
Who Discovered
Edwin McMillan and Philip H. Abelson
William Cruickshank
Discovery
In 1940
In 1787
Abundance
Abundance In Universe
Not Available
4 * 10-6 %
14
Abundance In Sun
~-9999 %
~0.000005 %
15
Abundance In Meteorites
Not Available
0.00 %
15
Abundance In Earth's Crust
Not Available
0.04 %
10
Abundance In Oceans
Not Available
0.00 %
4
Abundance In Humans
Not Available
0.00 %
7
Uses
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.
- Strontium metal is used to producing ferrite magnets as well as refining zinc.
- By-product of nuclear reactors called Strontium-90 is a radioactive isotope; it is absorbed by tissues and destroys bone marrow and cancer growth.
Industrial Uses
NA
Ammunition Industry, Chemical Industry
Medical Uses
NA
NA
Other Uses
Alloys, Nuclear Research, Research Purposes
Alloys
Biological Properties
Toxicity
Toxic
Non Toxic
Present in Human Body
No
Yes
In Blood
0.00 Blood/mg dm-3
37
0.03 Blood/mg dm-3
19
In Bone
0.00 p.p.m.
36
140.00 p.p.m.
7
Physical Properties
Melting Point
640.00 °C
99+
769.00 °C
99+
Boiling Point
3,902.00 °C
13
1,384.00 °C
99+
Appearance
Physical State
Solid
Solid
Color
Silver
Silvery White
Luster
Metallic
Metallic
Hardness
Mohs Hardness
Not Available
1.50
18
Speed of Sound
Not Available
Not Available
Optical Properties
Allotropes
No
No
α Allotropes
Not Available
Not Available
β Allotropes
Not Available
Not Available
γ Allotropes
Not Available
Not Available
Chemical Properties
Chemical Formula
Np
Sr
Isotopes
Known Isotopes
20
19
27
12
Electronegativity
Pauling Electronegativity
1.36
29
0.95
99+
Sanderson Electronegativity
Not Available
0.72
27
Allred Rochow Electronegativity
1.22
26
0.99
37
Mulliken-Jaffe Electronegativity
Not Available
1.00
18
Allen Electronegativity
Not Available
0.96
40
Electropositivity
Pauling Electropositivity
2.64
25
3.05
7
Ionization Energies
1st Energy Level
604.50 kJ/mol
99+
549.50 kJ/mol
99+
2nd Energy Level
1,128.00 kJ/mol
99+
1,064.20 kJ/mol
99+
3rd Energy Level
1,997.00 kJ/mol
99+
4,138.00 kJ/mol
10
4th Energy Level
3,242.00 kJ/mol
99+
5,500.00 kJ/mol
13
5th Energy Level
Not Available
6,910.00 kJ/mol
18
6th Energy Level
Not Available
8,760.00 kJ/mol
18
7th Energy level
Not Available
10,230.00 kJ/mol
19
8th Energy Level
Not Available
11,800.00 kJ/mol
19
9th Energy Level
Not Available
15,600.00 kJ/mol
17
10th Energy Level
Not Available
17,100.00 kJ/mol
19
11th Energy Level
Not Available
31,270.00 kJ/mol
6
Electrochemical Equivalent
1.77 g/amp-hr
39
1.64 g/amp-hr
99+
Electron Work Function
Not Available
2.59 eV
99+
Other Chemical Properties
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Ionization, Radioactive Isotopes, Radioactivity, Solubility
Atomic Properties
Atomic Number
93
25
38
99+
Electron Configuration
[Rn] 5f4 6d1 7s2
[Kr] 5s2
Crystal Structure
Orthorhombic (ORTH)
Face Centered Cubic (FCC)
Crystal Lattice
ORTH-Crystal-Structure-of-Neptunium.jpg#100
FCC-Crystal-Structure-of-Strontium.jpg#100
Atom
Number of Protons
93
25
38
99+
Number of Neutrons
144
14
50
99+
Number of Electrons
93
25
38
99+
Radius of an Atom
Atomic Radius
155.00 pm
30
215.00 pm
5
Covalent Radius
190.00 pm
18
195.00 pm
15
Van der Waals Radius
221.00 pm
22
249.00 pm
7
Atomic Weight
237.00 amu
22
87.62 amu
99+
Atomic Volume
11.62 cm3/mol
99+
33.70 cm3/mol
6
Adjacent Atomic Numbers
Valence Electron Potential
96.00 (-eV)
9
25.70 (-eV)
99+
Lattice Constant
666.30 pm
3
608.49 pm
6
Lattice Angles
π/2, π/2, π/2
π/2, π/2, π/2
Lattice C/A Ratio
Not Available
Not Available
Mechanical Properties
Density
Density At Room Temperature
19.38 g/cm3
14
2.64 g/cm3
99+
Density When Liquid (at m.p.)
Not Available
2.38 g/cm3
99+
Tensile Strength
125.00 MPa
14
Not Available
Viscosity
Not Available
Not Available
Vapor Pressure
Vapor Pressure at 1000 K
Not Available
121.00 (Pa)
1
Vapor Pressure at 2000 K
0.11 (Pa)
17
Not Available
Elasticity properties
Shear Modulus
Not Available
6.03 GPa
99+
Young's Modulus
Not Available
15.70 GPa
99+
Poisson Ratio
Not Available
0.28
17
Other Mechanical Properties
Ductile
NA
Magnetic Properties
Magnetic Characteristics
Specific Gravity
20.25
6
2.64
99+
Magnetic Ordering
Paramagnetic
Paramagnetic
Electrical Properties
Electrical Property
Conductor
NA
Resistivity
1.22 nΩ·m
99+
132.00 nΩ·m
24
Electrical Conductivity
0.01 106/cm Ω
99+
0.08 106/cm Ω
26
Electron Affinity
Not Available
5.03 kJ/mol
38
Thermal Properties
Specific Heat
0.12 J/(kg K)
40
0.30 J/(kg K)
18
Molar Heat Capacity
29.46 J/mol·K
8
26.40 J/mol·K
28
Thermal Conductivity
6.30 W/m·K
99+
35.40 W/m·K
37
Critical Temperature
Not Available
Not Available
Thermal Expansion
Not Available
22.50 µm/(m·K)
18
Enthalpy
Enthalpy of Vaporization
Not Available
150.00 kJ/mol
99+
Enthalpy of Fusion
3.20 kJ/mol
99+
9.16 kJ/mol
38
Enthalpy of Atomization
Not Available
163.20 kJ/mol
99+
Standard Molar Entropy
Not Available
55.00 J/mol.K
26
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