Einsteinium (Es)
Einsteinium (Es, element 99) is an actinide in period 7. Atomic mass 252, electron configuration [Rn] 5f¹¹ 7s², uses and facts.
About Einsteinium
Einsteinium is an actinide with the symbol Es and atomic number 99. It is a solid at room temperature, and it sits in period 7 of the periodic table. Einsteinium was discovered in 1952 by Albert Ghiorso.
Einsteinium key facts
- Atomic number: 99
- Symbol: Es
- Atomic mass: 252 u
- Category: actinide
- Group: none (f-block)
- Period: 7
- State at room temperature: solid
- Electron configuration: [Rn] 5f¹¹ 7s²
- Electronegativity (Pauling): 1.3
- Melting point: 1133 K (859.85 °C)
- Boiling point: 1269 K (995.85 °C)
- Density: 8.84 g/cm³
- Common oxidation states: +2, +3
Electron configuration
The electron configuration of einsteinium is [Rn] 5f¹¹ 7s². The part in brackets is the noble gas core; the rest shows how the outer electrons fill their subshells.
Uses of einsteinium
- Research only
- Synthesis of heavier elements
Did you know?
Discovered in the fallout of the first hydrogen bomb test in 1952. Named after Albert Einstein.
Neighbouring elements
- Californium (Cf)
- Fermium (Fm)
- 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 einsteinium?
The atomic number of einsteinium is 99, which means every einsteinium atom has 99 protons.
What is the electron configuration of einsteinium?
The electron configuration of einsteinium is [Rn] 5f¹¹ 7s².
What group and period is einsteinium in?
Einsteinium is an actinide in period 7.
What state is einsteinium at room temperature?
Einsteinium is a solid at room temperature.
What is einsteinium used for?
Einsteinium is used for research only, synthesis of heavier elements.