The American Chemical Society has adopted the following names for elements 101 to 110 for its primary and secondary publications. These names were adopted by IUPAC and endorsed by the ACS Committee on Nomenclature. The new names differ in only two cases from the names supported by the ACS Committee on Nomenclature and adopted by the ACS publications in 1995. Since 9/97, Dubnium replaced Hahnium for element 105 and Bohrium replaced Nielsbohrium for element 107.
| Element | New Name | Symbol | Previous CA Name | CAS Reg No |
|---|---|---|---|---|
| 101 | Mendelevium | Md | Mendelevium | 7440-11-1 |
| 102 | Nobelium | No | Nobelium | 10028-14-5 |
| 103 | Lawrencium | Lr | Lawrencium | 22537-19-5 |
| 104 | Rutherfordium | Rf | Rutherfordium | 53850-36-5 |
| => 105 | Dubnium | Db | Hahnium | 53850-35-4 |
| 106 | Seaborgium | Sg | Seaborgium | 54038-81-2 |
| => 107 | Bohrium | Bh | Nielsbohrium | 54037-14-8 |
| 108 | Hassium | Hs | Hassium | 54037-57-9 |
| 109 | Meitnerium | Mt | Meitnerium | 54038-01-06 |
| 110 | Darmstadtium | Ds | Ununnilium | 54083-77-1 |
The CAS REGISTRYSM nomenclature records for these two elements (and their isotopic and compound forms) are being updated to reflect the new names. Appropriate cross-references from the previous index names and synonyms will guide the users of the printed index. The previous names will also remain as synonyms in CAS REGISTRY.