Actinium(III) chloride, represented by the chemical formula AcCl3, is a chemical compound containing actinium and chlorine. In this compound, actinium is in the +3 oxidation state, meaning it has lost three electrons, and chlorine is in the -1 oxidation state, having gained one electron.

Actinium is a rare, radioactive element, and its isotopes are primarily used in scientific research and some medical applications. Actinium-227, for example, is a decay product of uranium-235 and is used as a neutron source and in radiation therapy for certain types of cancers.

As for actinium(III) chloride (AcCl3), it is not commonly encountered due to the rarity of actinium and its radioactive nature. Therefore, its practical uses are limited, and it is primarily of interest in scientific research and studies related to actinium chemistry. As with other radioactive compounds, proper safety measures and handling procedures are essential when working with actinium(III) chloride.