Einsteinium (Es) - Element 99 | Properties & Electron Configuration
What is Einsteinium?
Einsteinium (Es) is element 99, a actinide in period 7. Its electron configuration is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹¹ 6s² 6p⁶ 7s².
| Atomic Number | 99 |
| Symbol | Es |
| Atomic Mass | 252 u |
| Category | Actinide |
| Period | 7 |
| Group | N/A (f-block) |
| Block | f |
| Electron Configuration | 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹¹ 6s² 6p⁶ 7s² |
| Short Config | [Rn] 5f¹¹ 7s² |
| Electronegativity | 1.3 |
| Atomic Radius | N/A |
| Ionization Energy | 619 kJ/mol |
| Electron Affinity | N/A |
| Phase (STP) | Solid |
Electron Configuration
The full electron configuration of Einsteinium is 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰ 4s² 4p⁶ 4d¹⁰ 4f¹⁴ 5s² 5p⁶ 5d¹⁰ 5f¹¹ 6s² 6p⁶ 7s². In noble gas shorthand, this is written as [Rn] 5f¹¹ 7s².
Einsteinium is a f-block element, period 7.
Periodic Trends
Electronegativity: Einsteinium has a Pauling electronegativity of 1.3.
Ionization Energy: 619 kJ/mol. Ionization energy generally increases across a period and decreases down a group.
View all 118 elements with trend overlays for electronegativity, atomic radius, ionization energy, and electron affinity.
Explore Einsteinium on the Interactive Periodic Table