Actinoids - Electronic Configuration and Oxidation States

Actinoids

These are called second inner transition series. The elements in which the last electron enters one of the 5f-orbitals are called as actinoids (or) 5f-block elements. They include the elements from actinium (Ac) to Lawrencium (Lr). All these elements are radioactive and the elements beyond uranium are all man-made elements.

Comparison and Contrast between Actinoids and lanthanoids

Some significant similarities and differences between lanthanoids and actinoids are observed. They are discussed below:

Similarities

1. Both lanthanoids and actinoids involve in filling of f-orbitals.
2. Both exhibit common oxidation state of +3.
3. Both are electropositive and very reactive.
4. Both exhibit magnetic and spectral properties.
5. Lanthanoids exhibit lanthanide contraction and actinoids exhibit actinide contraction.

Differences between Lanthanoids and Actinoids