Periodic Table Element Comparison: Compare Elements - Promethium vs Americium
Compare Promethium and Americium on the basis of their properties, attributes and periodic table facts. Compare elements on more than 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 Promethium vs Americium with most reliable information about their properties, attributes, facts, uses etc. You can compare Pm vs Am on more than 90 properties like electronegativity , oxidation state, atomic shells, orbital structure, Electronaffinity, physical states, electrical conductivity and many more. Promethium and Americium comparison table on more than 90 properties.
Promethium and Americium Comparison
Facts
| Name | Promethium | Americium |
|---|---|---|
| Atomic Number | 61 | 95 |
| Atomic Symbol | Pm | Am |
| Atomic Weight | 145 | 243 |
| Phase at STP | Solid | Solid |
| Color | Silver | Silver |
| Metallic Classification | Lanthanide | Actinide |
| Group in Periodic Table | group - | group - |
| Group Name | ||
| Period in Periodic Table | period 6 | period 7 |
| Block in Periodic Table | f -block | f -block |
| Electronic Configuration | [Xe] 4f5 6s2 | [Rn] 5f7 7s2 |
| Electronic Shell Structure (Electrons per shell) | 2, 8, 18, 23, 8, 2 | 2, 8, 18, 32, 25, 8, 2 |
| Melting Point | 1373 K | 1449 K |
| Boiling Point | 3273 K | 2284 K |
| CAS Number | CAS7440-12-2 | CAS7440-35-9 |
| Neighborhood Elements | Neighborhood Elements of Promethium | Neighborhood Elements of Americium |
History
| Parameter | Promethium | Americium |
|---|---|---|
| History | The element Promethium was discovered by S. Wu,E.G. Segrè and H. Bethe in year 1942 in United States. Promethium derived its name from Prometheus of Greek mythology who stole fire from the Gods and gave it to humans. | The element Americium was discovered by G. T. Seaborg,R. A. James,O. Morgan and A. Ghiorso in year 1944 in United States. Americium derived its name from The Americas, as the element was first synthesized on the continent, by analogy with europium. |
| Discovery | S. Wu,E.G. Segrè and H. Bethe (1942) | G. T. Seaborg,R. A. James,O. Morgan and A. Ghiorso (1944) |
| Isolated | Charles D. Coryell,Jacob A. Marinsky,Lawrence E. Glendenin, and Harold G. Richter (1945) | () |
Presence: Abundance in Nature and Around Us
Parts per billion (ppb) by weight / by atoms (1ppb =10^-7 %)
| Property | Promethium | Americium |
|---|---|---|
| Abundance in Universe | - / - | - / - |
| Abundance in Sun | - / 0.005 | - / - |
| Abundance in Meteorites | - / - | - / - |
| Abundance in Earth's Crust | - / - | - / - |
| Abundance in Oceans | - / - | - / - |
| Abundance in Humans | - / - | - / - |
Crystal Structure and Atomic Structure
| Property | Promethium | Americium |
|---|---|---|
| Atomic Volume | 20.23 cm3/mol | 17.63 cm3/mol |
| Atomic Radius | 205 pm | 175 pm |
| Covalent Radius | - | - |
| Van der Waals Radius | - | - |
Atomic Spectrum - Spectral Lines | ||
| Emission Spectrum |  |  |
| Absorption Spectrum |  |  |
| Lattice Constant | - | 346.81, 346.81, 1124.1 pm |
| Lattice Angle | - | π/2, π/2, 2 π/3 |
| Space Group Name | - | P63/mmc |
| Space Group Number | - | 194 |
| Crystal Structure | Simple Hexagonal  | Simple Hexagonal |
Atomic and Orbital Properties
| Property | Promethium | Americium |
|---|---|---|
| Atomic Number | 61 | 95 |
| Number of Electrons (with no charge) | 61 | 95 |
| Number of Protons | 61 | 95 |
| Mass Number | 145 | 243 |
| Number of Neutrons | 84 | 148 |
| Shell structure (Electrons per energy level) | 2, 8, 18, 23, 8, 2 | 2, 8, 18, 32, 25, 8, 2 |
| Electron Configuration | [Xe] 4f5 6s2 | [Rn] 5f7 7s2 |
| Valence Electrons | 4f5 6s2 | 5f7 7s2 |
| Oxidation State | 3 | 3 |
| Atomic Term Symbol (Quantum Numbers) | 6H5/2 | 8S7/2 |
| Shell structure |  |  |
Isotopes and Nuclear Properties
Promethium has 1 stable naturally occuring isotopes while Americium has 0 stable naturally occuring isotopes.
| Parameter | Promethium | Americium |
|---|---|---|
| Known Isotopes | 126Pm, 127Pm, 128Pm, 129Pm, 130Pm, 131Pm, 132Pm, 133Pm, 134Pm, 135Pm, 136Pm, 137Pm, 138Pm, 139Pm, 140Pm, 141Pm, 142Pm, 143Pm, 144Pm, 145Pm, 146Pm, 147Pm, 148Pm, 149Pm, 150Pm, 151Pm, 152Pm, 153Pm, 154Pm, 155Pm, 156Pm, 157Pm, 158Pm, 159Pm, 160Pm, 161Pm, 162Pm, 163Pm | 231Am, 232Am, 233Am, 234Am, 235Am, 236Am, 237Am, 238Am, 239Am, 240Am, 241Am, 242Am, 243Am, 244Am, 245Am, 246Am, 247Am, 248Am, 249Am |
| Stable Isotopes | Naturally occurring stable isotopes: None | |
| Neutron Cross Section | 8000 | 74 |
| Neutron Mass Absorption | - | - |
Chemical Properties: Ionization Energies and electron affinity
| Property | Promethium | Americium |
|---|---|---|
| Valence or Valency | 3 | 4 |
| Electronegativity | 1.13 Pauling Scale | 1.13 Pauling Scale |
| Electron Affinity | 50 kJ/mol | - |
| Ionization Energies | 1st: 540 kJ/mol 2nd: 1050 kJ/mol 3rd: 2150 kJ/mol 4th: 3970 kJ/mol | 1st: 578 kJ/mol |
Physical Properties
| Property | Promethium | Americium |
|---|---|---|
| Density | 7.264 g/cm3 | 13.67 g/cm3 |
| Molar Volume | 20.23 cm3/mol | 17.63 cm3/mol |
Elastic Properties | ||
| Young Modulus | 46 | - |
| Shear Modulus | 18 GPa | - |
| Bulk Modulus | 33 GPa | - |
| Poisson Ratio | 0.28 | - |
Hardness - Tests to Measure of Hardness of Element | ||
| Mohs Hardness | - | - |
| Vickers Hardness | - | - |
| Brinell Hardness | - | - |
Electrical Properties | ||
| Electrical Conductivity | 1300000 S/m | - |
| Resistivity | 7.5e-7 m Ω | - |
| Superconducting Point | - | 0.6 |
Heat and Conduction Properties | ||
| Thermal Conductivity | 15 W/(m K) | 10 W/(m K) |
| Thermal Expansion | 0.000011 /K | - |
Magnetic Properties | ||
| Magnetic Type | - | Paramagnetic |
| Curie Point | - | - |
| Mass Magnetic Susceptibility | - | 5.15e-8 m3/kg |
| Molar Magnetic Susceptibility | - | 1.251e-8 m3/mol |
| Volume Magnetic Susceptibility | - | 0.000704 |
Optical Properties | ||
| Refractive Index | - | - |
Acoustic Properties | ||
| Speed of Sound | - | - |
Thermal Properties - Enthalpies and thermodynamics
| Property | Promethium | Americium |
|---|---|---|
| Melting Point | 1373 K | 1449 K |
| Boiling Point | 3273 K | 2284 K |
| Critical Temperature | - | - |
| Superconducting Point | - | 0.6 |
Enthalpies | ||
| Heat of Fusion | 7.7 kJ/mol | - |
| Heat of Vaporization | 290 kJ/mol | - |
| Heat of Combustion | - | - |
Regulatory and Health - Health and Safety Parameters and Guidelines
| Parameter | Promethium | Americium |
|---|---|---|
| CAS Number | CAS7440-12-2 | CAS7440-35-9 |
| RTECS Number | - | - |
| DOT Hazard Class | - | - |
| DOT Numbers | - | - |
| EU Number | - | - |
| NFPA Fire Rating | - | - |
| NFPA Health Rating | - | - |
| NFPA Reactivity Rating | - | - |
| NFPA Hazards | - | - |
| AutoIgnition Point | - | - |
| Flashpoint | - | - |
Compare With Other Elements
Compare Promethium and Americium with other elements of the periodic table.