Element Americium
It is a transuranic member of the actinide series, in the periodic table located under the lanthanide element europium, and thus by analogy was named after the Americas
Americium is a synthetic radioactive chemical element with the symbol Am and atomic number 95.
In the periodic table, americium is located to the right of plutonium, to the left of curium, and below the lanthanide europium, with which it shares many similarities in physical and chemical properties.
Americium is a highly radioactive element. When freshly prepared, it has a silvery-white metallic lustre, but then slowly tarnishes in air.
Names and Identifiers
| Chemical Formula: | Am |
| CAS: | 7440-35-9 |
| Molecular Weight: | 243.00000 g/mol |
| EC Number : | n/a |
| MDL Number: | n/a |
| Color: | silvery white |
| Other Names: | Americio |
| PubChem CID: | 23966 |
| IUPAC Name: | Americiu |
| Inchl: | InChI=1S/Am |
| InChI Key: | LXQXZNRPTYVCNG-UHFFFAOYSA-N |
| Canonical SMILES: | [Am] |
| ICSC Number: | n/a |
Physical & Chemical Properties
| Phase: | Solid |
| Density: | 12 g/cm³ |
| Boiling Point: | 2880 K (2607 °C, 4725 °F) |
| Melting Point: | 1449 K (1176 °C, 2149 °F) |
| Molecular Formula: | Am |
| Flash Point: | 1175ºC |
| Exact Mass: | 243.06100 |
About 19 isotopes and 8 nuclear isomers are known for americium. There are two long-lived alpha-emitters; 243Am has a half-life of 7,370 years and is the most stable isotope, and 241Am has a half-life of 432.2 years.
Radiosotope data
| Isotope | Mass/Da | Half-life | Mode of decay | Nuclear spin | Nuclear magnetic moment |
|---|---|---|---|---|---|
| 237Am | 237.0503 | 1.22 h | EC to 237Pu; α to 233Np | 5/2 | |
| 238Am | 238.05198 | 1.63 h | EC to 238Pu; α to 234Np | 1 | |
| 239Am | 239.05302 | 11.9 h | EC to 239Pu; α to 235Np | 5/2 | |
| 240Am | 240.05529 | 2.12 d | EC to 240Pu; α to 236Np | 3 | |
| 241Am | 241.05682 | 432.2 y | α to 237Np; SF | 5/2 | 1.61 |
| 242Am | 242.05654 | 16.02 h | EC to 242Pu; β– to 242Cm | 1 | 0.388 |
| 243Am | 243.061375 (3) | 7370 y | α to 239Np; SF | 5/2 | 1.61 |
| 244Am | 244.06428 | 10.1 h | β– to 244Cm | 1 | |
| 245Am | 245.06644 | 2.05 h | β– to 245Cm | 5/2 |