100 Fm 257
Fermium
Actinide
Fermium (Fm) is a chemical element with atomic number 100, classified as a actinide. At room temperature it is a solid. It was discovered in 1952 by Albert Ghiorso et al..
Properties
- Atomic number
- 100
- Atomic mass
- 257 u
- Category
- Actinide
- Group
- 0
- Period
- 7
- Block
- f-block
- Electron configuration
- [Rn] 5f¹² 7s²
- Phase at STP
- Solid
- Density
- —
- Melting point
- 1800 K (1526.8 °C)
- Boiling point
- —
- Electronegativity
- 1.3
- Atomic radius
- —
- Ionization energy
- 6.5 eV
- Discovery
- 1952 · Albert Ghiorso et al.
Common uses
Research only
Did you know?
Named after Enrico Fermi and discovered in hydrogen bomb tests.
Experiment with the elements
Fermium doesn't form any compounds in our lab yet, but the periodic table sandbox lets you combine dozens of other real elements into real compounds — water, table salt, ammonia and many more — with their true chemical formulas.