Actinide concept
= Actinide concept
{wiki=Actinide_concept}
The Actinide concept refers to a family of chemical elements in the periodic table that includes the 15 elements from actinium (Ac, atomic number 89) to lawrencium (Lr, atomic number 103). These elements are part of the f-block of the periodic table and are characterized by the filling of the 5f orbital. The actinides are known for their complex electronic structures and their tendency to form various oxidation states.