Actinides

Actinides or actinoids is a generic term that refers to a series of 15 chemical elements. Denoted by the generic symbol An, these elements are all radioactive heavy metals, positioned in the seventh period and elaborated upon at the bottom of the periodic table.

All actinide metals are prepared on a scale by the reduction of AnF₃ or AnF₄ with vapors of lithium (Li), magnesium (Mg), calcium (Ca), or barium (Ba) at 2,102–2,552°F (1,150–1,400°C); sometimes chlorides or oxides are used. The Van Arkel-de Boer process is a special preparation method used for thorium and protactinium.