Actinium is a member of the actinide series of elements. It is a rare element. In fact, it is one of the first non-primordial radioactive elements to be isolated.
Actinium is a member of group three on the periodic table. This group includes fifteen chemical elements. Several of them are synthetic, but the rest are naturally occurring.
Actinium is considered to be the first of the actinides. The actinides are characterized by a gradual filling of the 5f subshell.
Because of its physical and chemical properties, it closely resembles lanthanum. However, it differs in the ionic radii of its isotopes. For instance, its valence electrons are only three.
Actinium is produced in a variety of ways. Most commonly, it is obtained by neutron irradiation of the radium isotope 226Ra in a nuclear reactor. However, it is also a precursor to other radioactive isotopes. Some of its applications include a neutron source, and a radiation therapy agent.
Actinium is an attractive candidate for future radioisotope thermoelectric generators. It has an atomic radius of 195 pm. It emits alpha rays and glows when it is irradiated. When it is in gaseous form, it does not have any 5f electrons.
Actinium is an element that is found in nature. A trace amount of it is found in uranium ore. One tonne of uranium ore contains 0.2 milligrams of the isotope 227Ac.
The atomic radius of actinium is 195 pm. It has 89 protons and 138 neutrons.