The inner transition metals are also known as rare earth metals. The rare earth metals includes Lanthanide and Actinide Series of the periodic table. The elements with atomic numbers 89 to 103 are placed in the third group of the periodic table are Actinides. Examples are uranium and plutonium. These elements are with high oxidation number are radioactive elements. Thus, the inner transition metals are radioactive elements.
The inner transition metals consists mostly of the f-block elements. They comprise of lanthanides and actinides. Many of them are radioactive because they possess atomic numbers greater than 82, hence their nuclei are unstable. Many of them are synthetic elements hence they are highly radioactive with very short half lives.
