Atomic Number: 89

Protons: 89

Electrons: 89

Neutrons: 138

Average Atomic Mass: 227

Isotopes: Ac-224, Ac-225, Ac-226, Ac-227, Ac228, and Ac229

Discovery: Andre Debierne in 1899, and F.Giesel in 1902 but using different techniques.

Name: The name Actinium comes from the Greek word "aktinos" meaning "ray."

Uses: Actinium is a source of thermoelectric power, as well as a source of neutrons

Interesting Facts: Glows blue in the dark due to radioactivity and is more dangerous than plutonium.