| Name | einsteinium |
|---|---|
| Symbol | Es |
| Atomic Weight | 252.08 |
| Atomic Number | 99 |
| CAS ID | 7429-92-7 |
| Group Number | (none) |
| Group Name | Actinoid |
| Period Number | 7 |
| Origin of Name | Named after Albert Einstein. |
| Year Discovered | 1952 |
| Discovery Credits | Discovered in the debris of the 1952 thermonuclear explosion in the Pacific by G. R. Choppin, S. G. Thompson, A. Ghlorso, and B. G. Harvey. |
| Class | Metallic |
| Color | Unknown, but probably metallic and silvery white or gray in appearance. |
| Standard State | Solid at 77 F & 298 K |
| Description | Radioactive, silvery metal which does not occur naturally. attacked by oxygen, steam, and acids, but not alkalis. |