Einsteinium
einsteinium atom
識別子と物理属性
| CAS No. | 7429-92-7 |
|---|---|
| 分子式 | Es |
| 平均分子量 | 252.083 g/mol |
| 単同位体質量 | 252.083 g/mol |
| SMILES | [Es] |
| InChIKey | CKBRQZNRCSJHFT-UHFFFAOYSA-N |
| PubChem CID | 23913 |
| ChEBI | CHEBI:33393 |
| DTXSID | DTXSID30225305 |
化学・物理的性質
| 極性表面積 | 0 |
|---|---|
| 水素結合供与体数 | 0 |
| 水素結合受容体数 | 0 |
| 回転可能結合数 | 0 |
| 重原子数 | 1 |
| 形式電荷 | 0 |
| 複雑度 | 0 |
| 物質分類 | Physical/Radiation -> Radionuclides |
| SpringerMaterials Properties | nuclear state |
| Physical Description | A metal with a melting point of about 860 degrees C[Merck Index] |
| 融点 | 860 ±50° |
| 密度 | 8.84 |
| 外観・状態 | 金属 |
| 色 | metalcubic |
| Bulk Modulus | 15.0 GPa, Estimated |
| CAS データベース | 7429-92-7 |
化学的特性
man-made radioisotope; identified by Ghiorso and colleagues at Berkeley in December 1952, as part of debris from first large thermonuclear explosion; chemical properties similar to those of holmium; ionic radius of Es+++ is 0.0925 nm; has lowest enthalpy of vaporization of any of the divalent elements; cub, a=0.575 nm; discovered in 1952; t1/2 of 253Es is 20.5 days, t1/2 of 254Es is 276 days, t1/2 of 255Es is 40 days [HAW93] [KIR78]
安全性と法規制
| 有害性の概要 | Most Important Radionuclide: Es-254 Source: Neutron bombardment of plutoniumHalf-Life: 472 days Lung Clearance Half-Time: Weeks Internal Toxicity: Very High Annual Limit on Intake: 0.00002 mCi[See Glossary for references.] See Radiation, ionizing. |
|---|
用途
来歴
The name of Es derives from “Albert Einstein”, the Geituan born physicist who proposed the theory of relativity. A collaboration of American scientists G. R. Choppin, S. G. Thompson, A. Ghiorso, and B. G. Harvey, from the Argonne National Laboratory near Chicago, Illinois, the Los Alamos Scientific Laboratory in Los Alamos, New Mexico and at the University of California lab in Berkeley, CA, first found 252Es in the radioactive debris from the first large thermonuclear bomb explosion, nicknamed “Mike,” which took place at Enewetak atoll, Marshall Islands in the Pacific on November 1, 1952. The longest halflife associated with this unstable element is 472 day 252Es.