Compare Neptunium vs Silicon: Periodic Table Element Comparison Table and Properties
Compare the elements Neptunium and Silicon on the basis of their properties, attributes and periodic table facts. Compare elements - Neptunium and Silicon comparison table side by side across over 90 properties. All the elements of similar categories show a lot of similarities and differences in their chemical, atomic, physical properties and uses. These similarities and dissimilarities should be known while we study periodic table elements. You can study the detailed comparison between Neptunium vs Silicon with most reliable information about their properties, attributes, facts, uses etc. You can compare Np vs Si on more than 90 properties like electronegativity, oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. This in-depth comparison helps students, educators, researchers, and science enthusiasts understand the differences and similarities between Neptunium and Silicon.
Neptunium and Silicon Comparison
Here's a detailed comparison between Neptunium (Np) and Silicon (Si), focusing on their position in the periodic table, physical and chemical properties, stability, and uses.
Facts - Basic Element Details
| Name | Neptunium | Silicon |
|---|---|---|
| Atomic Number | 93 | 14 |
| Atomic Symbol | Np | Si |
| Atomic Weight | 237 | 28.0855 |
| Phase at STP | Solid | Solid |
| Color | Silver | Gray |
| Metallic Classification | Actinide | Metalloid |
| Group in Periodic Table | Actinide (no group number) | group 14 |
| Group Name | carbon family | |
| Period in Periodic Table | period 7 | period 3 |
| Block in Periodic Table | f -block | p -block |
| Electronic Configuration | [Rn] 5f4 6d1 7s2 | [Ne] 3s2 3p2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 32, 22, 9, 2 | 2, 8, 4 |
| Melting Point | 917 K | 1687 K |
| Boiling Point | 4273 K | 3173 K |
| CAS Number | CAS7439-99-8 | CAS7440-21-3 |
| Neighborhood Elements | Neighborhood Elements of Neptunium | Neighborhood Elements of Silicon |
History
| Parameter | Neptunium | Silicon |
|---|---|---|
| History | The element Neptunium was discovered by E.M. McMillan and H. Abelson in year 1940 in United States. Neptunium derived its name from Neptune, the eighth planet in the Solar System. | The element Silicon was discovered by J. Berzelius in year 1823 in Sweden. Silicon derived its name from the Latin silex, 'flint' (originally silicium). |
| Discovery | E.M. McMillan and H. Abelson (1940) | J. Berzelius (1823) |
| Isolated | () | J. Berzelius (1823) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Neptunium | Silicon |
|---|---|---|
| Abundance in Universe | - / - | 700000 / 30000 |
| Abundance in Sun | - / - | 900000 / 40000 |
| Abundance in Meteorites | - / - | 140000000 / 100000000 |
| Abundance in Earth's Crust | - / - | 270000000 / 200000000 |
| Abundance in Oceans | - / - | 1000 / 220 |
| Abundance in Humans | - / - | 260000 / 58000 |
Crystal Structure and Atomic Structure
| Property | Neptunium | Silicon |
|---|---|---|
| Atomic Volume | 11.5892 cm3/mol | 12.054 cm3/mol |
| Atomic Radius | 175 pm | 111 pm |
| Covalent Radius | - | 111 pm |
| Van der Waals Radius | - | 210 pm |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum | Not available | ![]() |
| Absorption Spectrum | ![]() | |
| Lattice Constant | 666.3, 472.3, 488.7 pm | 543.09, 543.09, 543.09 pm |
| Lattice Angle | π/2, π/2, π/2 | π/2, π/2, π/2 |
| Space Group Name | Pnma | Fd_ 3m |
| Space Group Number | 62 | 227 |
| Crystal Structure | Simple Orthorhombic ![]() | Tetrahedral Packing ![]() |
Atomic and Orbital Properties
| Property | Neptunium | Silicon |
|---|---|---|
| Atomic Number | 93 | 14 |
| Number of Electrons (with no charge) | 93 | 14 |
| Number of Protons | 93 | 14 |
| Mass Number | 237 | 28.0855 |
| Number of Neutrons | 144 | 14 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 32, 22, 9, 2 | 2, 8, 4 |
| Electron Configuration | [Rn] 5f4 6d1 7s2 | [Ne] 3s2 3p2 |
| Valence Electrons | 5f4 6d1 7s2 | 3s2 3p2 |
| Oxidation State | 5 | -4, 4 |
| Atomic Term Symbol (Quantum Numbers) | 6L11/2 | 3P0 |
| Shell structure | ![]() | ![]() |
Isotopes and Nuclear Properties
Neptunium has 0 stable naturally occuring isotopes while Silicon has 3 stable naturally occuring isotopes.
| Parameter | Neptunium | Silicon |
|---|---|---|
| Known Isotopes | 225Np, 226Np, 227Np, 228Np, 229Np, 230Np, 231Np, 232Np, 233Np, 234Np, 235Np, 236Np, 237Np, 238Np, 239Np, 240Np, 241Np, 242Np, 243Np, 244Np | 22Si, 23Si, 24Si, 25Si, 26Si, 27Si, 28Si, 29Si, 30Si, 31Si, 32Si, 33Si, 34Si, 35Si, 36Si, 37Si, 38Si, 39Si, 40Si, 41Si, 42Si, 43Si, 44Si |
| Stable Isotopes | - | Naturally occurring stable isotopes: 28Si, 29Si, 30Si |
| Neutron Cross Section | 180 | 171 |
| Neutron Mass Absorption | - | 0.0002 |
Chemical Properties: Ionization Energies and electron affinity
| Property | Neptunium | Silicon |
|---|---|---|
| Valence or Valency | 6 | 4 |
| Electronegativity | 1.36 Pauling Scale | 1.9 Pauling Scale |
| Oxidation State | 5 | -4, 4 |
| Electron Affinity | - | 133.6 kJ/mol |
| Ionization Energies | 1st: 604.5 kJ/mol | 1st: 786.5 kJ/mol 2nd: 1577.1 kJ/mol 3rd: 3231.6 kJ/mol 4th: 4355.5 kJ/mol 5th: 16091 kJ/mol 6th: 19805 kJ/mol 7th: 23780 kJ/mol 8th: 29287 kJ/mol 9th: 33878 kJ/mol 10th: 38726 kJ/mol 11th: 45962 kJ/mol 12th: 50502 kJ/mol 13th: 235196 kJ/mol 14th: 257923 kJ/mol |
Physical Properties
Silicon (2.33 g/cm³) is less dense than Neptunium (20.45 g/cm³). This means that a given volume of Neptunium will be heavier than the same volume of Silicon. Neptunium is about 777.7 denser than Silicon
| Property | Neptunium | Silicon |
|---|---|---|
| Phase at STP | Solid | Solid |
| Color | Silver | Gray |
| Density | 20.45 g/cm3 | 2.33 g/cm3 |
| Density (when liquid (at melting point)) | - | 2.57 g/cm3 |
| Molar Volume | 11.5892 cm3/mol | 12.054 cm3/mol |
Mechanical and Hardness Properties
| Property | Neptunium | Silicon |
|---|---|---|
Elastic Properties | ||
| Young Modulus | - | 47 |
| Shear Modulus | - | - |
| Bulk Modulus | - | 100 GPa |
| Poisson Ratio | - | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | - | 6.5 MPa |
| Vickers Hardness | - | - |
| Brinell Hardness | - | - |
Thermal and Electrical Conductivity
| Property | Neptunium | Silicon |
|---|---|---|
Heat and Conduction Properties | ||
| Thermal Conductivity | 6 W/(m K) | 150 W/(m K) |
| Thermal Expansion | - | 0.0000026 /K |
Electrical Properties | ||
| Electrical Conductivity | 830000 S/m | 1000 S/m |
| Resistivity | 0.0000012 m Ω | 0.001 m Ω |
| Superconducting Point | - | - |
Magnetic and Optical Properties
| Property | Neptunium | Silicon |
|---|---|---|
Magnetic Properties | ||
| Magnetic Type | - | Diamagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | - | -1.6e-9 m3/kg |
| Molar Magnetic Susceptibility | - | -4.49e-11 m3/mol |
| Volume Magnetic Susceptibility | - | -0.00000373 |
Optical Properties | ||
| Refractive Index | - | - |
Acoustic Properties | ||
| Speed of Sound | - | 2200 m/s |
Thermal Properties - Enthalpies and thermodynamics
| Property | Neptunium | Silicon |
|---|---|---|
| Melting Point | 917 K | 1687 K |
| Boiling Point | 4273 K | 3173 K |
| Critical Temperature | - | - |
| Superconducting Point | - | - |
Enthalpies | ||
| Heat of Fusion | 10 kJ/mol | 50.2 kJ/mol |
| Heat of Vaporization | 335 kJ/mol | 359 kJ/mol |
| Heat of Combustion | - | -9055 J/(kg K) |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Neptunium | Silicon |
|---|---|---|
| CAS Number | CAS7439-99-8 | CAS7440-21-3 |
| RTECS Number | - | RTECSVW0400000 |
| DOT Hazard Class | - | 4.1 |
| DOT Numbers | - | 1346 |
| EU Number | - | - |
| NFPA Fire Rating | - | 0 |
| NFPA Health Rating | - | 1 |
| NFPA Reactivity Rating | - | 0 |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | 150 °C |
| Flashpoint | - | - |
Compare Neptunium and Silicon With Other Elements
Compare Neptunium and Silicon with other elements of the periodic table. Explore howNeptunium and Silicon stack up against other elements of the periodic table. Use our interactive comparison tool to analyze 90+ properties across different metals, non-metals, metalloids, and noble gases. Understanding these differences is crucial for applications in engineering, chemistry, electronics, biology, and material science.






