Compare Selenium vs Protactinium: Periodic Table Element Comparison Table and Properties
Compare the elements Selenium and Protactinium on the basis of their properties, attributes and periodic table facts. Compare elements - Selenium and Protactinium 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 Selenium vs Protactinium with most reliable information about their properties, attributes, facts, uses etc. You can compare Se vs Pa 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 Selenium and Protactinium.
Selenium and Protactinium Comparison
Here's a detailed comparison between Selenium (Se) and Protactinium (Pa), focusing on their position in the periodic table, physical and chemical properties, stability, and uses.
Facts - Basic Element Details
| Name | Selenium | Protactinium |
|---|---|---|
| Atomic Number | 34 | 91 |
| Atomic Symbol | Se | Pa |
| Atomic Weight | 78.96 | 231.03588 |
| Phase at STP | Solid | Solid |
| Color | Gray | Silver |
| Metallic Classification | Other Nonmetal | Actinide |
| Group in Periodic Table | group 16 | Actinide (no group number) |
| Group Name | oxygen family | |
| Period in Periodic Table | period 4 | period 7 |
| Block in Periodic Table | p -block | f -block |
| Electronic Configuration | [Ar] 3d10 4s2 4p4 | [Rn] 5f2 6d1 7s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 6 | 2, 8, 18, 32, 20, 9, 2 |
| Melting Point | 494 K | 1845 K |
| Boiling Point | 958 K | 4273 K |
| CAS Number | CAS7782-49-2 | CAS7440-13-3 |
| Neighborhood Elements | Neighborhood Elements of Selenium | Neighborhood Elements of Protactinium |
History
| Parameter | Selenium | Protactinium |
|---|---|---|
| History | The element Selenium was discovered by J. Berzelius and G. Gahn in year 1817 in Sweden. Selenium derived its name from the Greek selene, meaning 'moon'. | The element Protactinium was discovered by O. H. Göhring and K. Fajans in year 1913 in Germany and United Kingdom. Protactinium derived its name from the Greek protos, 'first', and actinium, which is produced through the radioactive decay of protactinium. |
| Discovery | J. Berzelius and G. Gahn (1817) | O. H. Göhring and K. Fajans (1913) |
| Isolated | J. Berzelius and G. Gahn (1817) | A. von Grosse (1927) |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Selenium | Protactinium |
|---|---|---|
| Abundance in Universe | 30 / 0.5 | - / - |
| Abundance in Sun | - / - | - / - |
| Abundance in Meteorites | 13000 / 2900 | - / - |
| Abundance in Earth's Crust | 50 / 10 | 0.000010 / 0.0000009 |
| Abundance in Oceans | 0.45 / 0.035 | 0.0000000000000002 / 0.000000000000000005 |
| Abundance in Humans | 50 / 4 | - / - |
Crystal Structure and Atomic Structure
| Property | Selenium | Protactinium |
|---|---|---|
| Atomic Volume | 16.385 cm3/mol | 15.18 cm3/mol |
| Atomic Radius | 103 pm | 180 pm |
| Covalent Radius | 116 pm | - |
| Van der Waals Radius | 190 pm | - |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | 905.4, 908.3, 1160.1 pm | 392.5, 392.5, 323.8 pm |
| Lattice Angle | π/2, 1.58493, π/2 | π/2, π/2, π/2 |
| Space Group Name | P121/c1 | I4/mmm |
| Space Group Number | 14 | 139 |
| Crystal Structure | Simple Monoclinic  | Centered Tetragonal  |
Atomic and Orbital Properties
| Property | Selenium | Protactinium |
|---|---|---|
| Atomic Number | 34 | 91 |
| Number of Electrons (with no charge) | 34 | 91 |
| Number of Protons | 34 | 91 |
| Mass Number | 78.96 | 231.03588 |
| Number of Neutrons | 45 | 140 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 6 | 2, 8, 18, 32, 20, 9, 2 |
| Electron Configuration | [Ar] 3d10 4s2 4p4 | [Rn] 5f2 6d1 7s2 |
| Valence Electrons | 4s2 4p4 | 5f2 6d1 7s2 |
| Oxidation State | -2, 2, 4, 6 | 5 |
| Atomic Term Symbol (Quantum Numbers) | 3P2 | 4K11/2 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Selenium has 5 stable naturally occuring isotopes while Protactinium has 0 stable naturally occuring isotopes.
| Parameter | Selenium | Protactinium |
|---|---|---|
| Known Isotopes | 65Se, 66Se, 67Se, 68Se, 69Se, 70Se, 71Se, 72Se, 73Se, 74Se, 75Se, 76Se, 77Se, 78Se, 79Se, 80Se, 81Se, 82Se, 83Se, 84Se, 85Se, 86Se, 87Se, 88Se, 89Se, 90Se, 91Se, 92Se, 93Se, 94Se | 212Pa, 213Pa, 214Pa, 215Pa, 216Pa, 217Pa, 218Pa, 219Pa, 220Pa, 221Pa, 222Pa, 223Pa, 224Pa, 225Pa, 226Pa, 227Pa, 228Pa, 229Pa, 230Pa, 231Pa, 232Pa, 233Pa, 234Pa, 235Pa, 236Pa, 237Pa, 238Pa, 239Pa, 240Pa |
| Stable Isotopes | Naturally occurring stable isotopes: 74Se, 76Se, 77Se, 78Se, 80Se | |
| Neutron Cross Section | 11.7 | 500 |
| Neutron Mass Absorption | 0.0056 | - |
Chemical Properties: Ionization Energies and electron affinity
| Property | Selenium | Protactinium |
|---|---|---|
| Valence or Valency | 6 | 5 |
| Electronegativity | 2.55 Pauling Scale | 1.5 Pauling Scale |
| Oxidation State | -2, 2, 4, 6 | 5 |
| Electron Affinity | 195 kJ/mol | - |
| Ionization Energies | 1st: 941 kJ/mol 2nd: 2045 kJ/mol 3rd: 2973.7 kJ/mol 4th: 4144 kJ/mol 5th: 6590 kJ/mol 6th: 7880 kJ/mol 7th: 14990 kJ/mol | 1st: 568 kJ/mol |
Physical Properties
Selenium (4.819 g/cm³) is less dense than Protactinium (15.37 g/cm³). This means that a given volume of Protactinium will be heavier than the same volume of Selenium. Protactinium is about 218.9 denser than Selenium
| Property | Selenium | Protactinium |
|---|---|---|
| Phase at STP | Solid | Solid |
| Color | Gray | Silver |
| Density | 4.819 g/cm3 | 15.37 g/cm3 |
| Density (when liquid (at melting point)) | 3.99 g/cm3 | - |
| Molar Volume | 16.385 cm3/mol | 15.18 cm3/mol |
Mechanical and Hardness Properties
| Property | Selenium | Protactinium |
|---|---|---|
Elastic Properties | ||
| Young Modulus | 10 | - |
| Shear Modulus | 3.7 GPa | - |
| Bulk Modulus | 8.3 GPa | - |
| Poisson Ratio | 0.33 | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | 2 MPa | - |
| Vickers Hardness | - | - |
| Brinell Hardness | 736 MPa | - |
Thermal and Electrical Conductivity
| Property | Selenium | Protactinium |
|---|---|---|
Heat and Conduction Properties | ||
| Thermal Conductivity | 0.52 W/(m K) | 47 W/(m K) |
| Thermal Expansion | - | - |
Electrical Properties | ||
| Electrical Conductivity | - | 5600000 S/m |
| Resistivity | - | 1.8e-7 m Ω |
| Superconducting Point | - | 1.4 |
Magnetic and Optical Properties
| Property | Selenium | Protactinium |
|---|---|---|
Magnetic Properties | ||
| Magnetic Type | Diamagnetic | Paramagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | -4e-9 m3/kg | 3.25e-8 m3/kg |
| Molar Magnetic Susceptibility | -3.16e-10 m3/mol | 7.509e-9 m3/mol |
| Volume Magnetic Susceptibility | -0.0000193 | 0.0004995 |
Optical Properties | ||
| Refractive Index | 1.000895 | - |
Acoustic Properties | ||
| Speed of Sound | 3350 m/s | - |
Thermal Properties - Enthalpies and thermodynamics
| Property | Selenium | Protactinium |
|---|---|---|
| Melting Point | 494 K | 1845 K |
| Boiling Point | 958 K | 4273 K |
| Critical Temperature | 1766 K | - |
| Superconducting Point | - | 1.4 |
Enthalpies | ||
| Heat of Fusion | 5.4 kJ/mol | 15 kJ/mol |
| Heat of Vaporization | 26 kJ/mol | 470 kJ/mol |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Selenium | Protactinium |
|---|---|---|
| CAS Number | CAS7782-49-2 | CAS7440-13-3 |
| RTECS Number | {N/A, RTECSVS7700000, N/A} | - |
| DOT Hazard Class | 6.1 | - |
| DOT Numbers | 2658 | - |
| EU Number | - | - |
| NFPA Fire Rating | 0 | - |
| NFPA Health Rating | 2 | - |
| NFPA Reactivity Rating | 0 | - |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | - |
| Flashpoint | - | - |
Compare Selenium and Protactinium With Other Elements
Compare Selenium and Protactinium with other elements of the periodic table. Explore howSelenium and Protactinium 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.