99 Es
Actinide
Einsteinium
From nuclear test fallout.
Properties of Einsteinium
- Atomic number (Z)
- 99
- Symbol
- Es
- Atomic mass
- 252 g/mol
- Category
- Actinide
- Group
- 3
- Period
- 7
- Electron configuration
- [Rn] 5f¹¹ 7s²
- Electronegativity (Pauling)
- 1.3
- Atomic radius
- —
- First ionization energy
- 619 kJ/mol
- Melting point
- 1133 K (859.9 °C)
- Boiling point
- 1269 K (995.9 °C)
- Density
- 8.84 g/cm³
- Phase at 25 °C
- Solid
- Discovered
- Discovered in 1952
Frequently asked questions
What is Einsteinium?
Einsteinium (Es) is an actinide, element number 99 on the periodic table. From nuclear test fallout.
What is the atomic number and atomic mass of Einsteinium?
Einsteinium has atomic number 99 and an atomic mass of about 252 g/mol.
What is the electron configuration of Einsteinium?
The electron configuration of Einsteinium is [Rn] 5f¹¹ 7s².
Where is Einsteinium on the periodic table?
Einsteinium sits in group 3, period 7, and is classified as a actinide.