100
Fm
257
Fermium
Actinide
Period 7
Block f
Fermium is a chemical element of the periodic table with chemical symbol Fm and atomic number 100 with an atomic weight of 257 u and is classed as actinide. Fermium is solid at room temperature.
Fermium in the periodic table
| Symbol | Fm |
| Atomic number | 100 |
| Group | - |
| Period | 7 |
| Block | f |
| Classification | Actinide |
| Appearance | - |
| Color | - |
| Number of protons | 100 p+ |
| Number of neutrons | 157 n0 |
| Number of electrons | 100 e- |
From Wikipedia, the free encyclopediaFermium is a synthetic element with symbol Fm and atomic number 100. It is a member of the actinide series. It is the heaviest element that can be formed by neutron bombardment of lighter elements, and hence the last element that can be prepared in macroscopic quantities, although pure fermium metal has not yet been prepared.
Physical properties
| Phase at STP | Solid |
| Density | 0 g/cm3 |
| Atomic weight | 257 u |
Thermal properties
| Melting point | 1800 K 1526.85 °C 2780.33 °F |
| Boiling point | - |
| Heat of vaporization | - |
Atomic properties
| Electronegativity (Pauling Scale) | 1.3 |
| Electron affinity | 33.96 kJ/mol |
| Oxidation states | +2, +3 () |
| Ionization energies |
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Electron configuration for fermium
Electron configuration Shorthand configuration | [Rn] 5f12 7s2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Full configuration | 1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14 5s2 5p6 5d10 5f12 6s2 6p6 7s2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Electron configuration chart |
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| Electrons per shell | 2, 8, 18, 32, 30, 8, 2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Outer shell electrons | 2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Valency electrons | 3 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bohr model | Figure: Shell diagram of Fermium (Fm) atom. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Orbital Diagram
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The history of Fermium
| Discovery | Lawrence Berkeley National Laboratory (1952) |
Discovery of fermium Fermium was also discovered in the debris of the Ivy Mike thermonuclear test of November 1952, identified by Albert Ghiorso's team at Berkeley alongside einsteinium. Like its sister discovery it was kept classified until 1955. The element was named after the Italian-American physicist Enrico Fermi, who built the first nuclear reactor and died in 1954. | |
| Original word | Fermi |
| Language of origin | English |
| Name source | Person |
| Meaning | “Enrico Fermi” |
Naming The element is named in honour of Enrico Fermi, the Italian-American physicist who built the first nuclear reactor. | |