Actinide
|
|
| Atomic No. | Name | Symbol |
|---|---|---|
| 90 | Thorium | Th |
| 91 | Protactinium | Pa |
| 92 | Uranium | U |
| 93 | Neptunium | Np |
| 94 | Plutonium | Pu |
| 95 | Americium | Am |
| 96 | Curium | Cm |
| 97 | Berkelium | Bk |
| 98 | Californium | Cf |
| 99 | Einsteinium | Es |
| 100 | Fermium | Fm |
| 101 | Mendelevium | Md |
| 102 | Nobelium | No |
| 103 | Lawrencium | Lr |
The actinide series encompasses the 14 chemical elements that lie between thorium and lawrencium on the periodic table with atomic numbers 90 - 103 inclusive. The actinide series is named after actinium, and this element is often included in the series by convention. All actinides are f-block elements except lawrencium. A strict correlation between periodic table blocks and chemical series would include actinium in the series and place lawrencium in the transition metals. This approach is gaining some popularity.
Actinides have chemically similar characteristics to the elements of the lanthanide series, and to scandium and yttrium, but actinides are all radioactive. The actinides with higher atomic numbers are not found in nature and have short half-lives.
The actinides are typically placed below the main body of the periodic table, in the manner of a footnote. The full-width version of the periodic table shows the position of the actinides more clearly.
Actinide_phases.gif
de:Actinoide et:Aktinoid es:Actínido eo:Aktinoido fr:Actinide it:Attinidi ja:アクチノイド pl:Aktynowce nl:Actinide ru:Актиноиды tr:Aktinit zh:锕系元素