Fermium (Fm)
Fermium (Fm, element 100) is an actinide in period 7. Atomic mass 257, electron configuration [Rn] 5f¹² 7s², uses and facts.
About Fermium
Fermium is an actinide with the symbol Fm and atomic number 100. It is a solid at room temperature, and it sits in period 7 of the periodic table. Fermium was discovered in 1952 by Albert Ghiorso.
Fermium key facts
- Atomic number: 100
- Symbol: Fm
- Atomic mass: 257 u
- Category: actinide
- Group: none (f-block)
- Period: 7
- State at room temperature: solid
- Electron configuration: [Rn] 5f¹² 7s²
- Electronegativity (Pauling): 1.3
- Melting point: 1800 K (1526.85 °C)
- Boiling point: not known
- Density: not known
- Common oxidation states: +2, +3
Electron configuration
The electron configuration of fermium is [Rn] 5f¹² 7s². The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells.
Uses of fermium
- Research only
Did you know?
Also discovered in H-bomb fallout. Named after Enrico Fermi, who created the first nuclear reactor.
Neighbouring elements
- Einsteinium (Es)
- Mendelevium (Md)
- Actinium (Ac)
- Thorium (Th)
- Protactinium (Pa)
- Uranium (U)
- Neptunium (Np)
- Plutonium (Pu)
- Americium (Am)
- Curium (Cm)
Frequently asked questions
What is the atomic number of fermium?
The atomic number of fermium is 100, which means every fermium atom has 100 protons.
What is the electron configuration of fermium?
The electron configuration of fermium is [Rn] 5f¹² 7s².
What group and period is fermium in?
Fermium is an actinide in period 7.
What state is fermium at room temperature?
Fermium is a solid at room temperature.
What is fermium used for?
Fermium is used for research only.