Inner transition metals are the elements of two series which are known as lanthanoids and actinoids. They occupy the ‘f’ block elements are shown below all the other elements in periodic table. But they belong to the periods 6 and 7. The lanthanoid series consists of 14 elements which starts from cerium and ends to lutetium (atomic numbers 58-71). Similarly, actinoids consists of 14 elements from thorium to lawrencium (atomic numbers 90-103), which follow actinium. Most of the actinoids were synthesized through nuclear reactions, not generated naturally.
The elements in the lanthanoids series are very similar to each other. They are used to produce sunglasses lenses, lasers, and strong magnets. The two well known elements are uranium and plutonium, which are mainly used in nuclear weapons and nuclear power plants and generate electricity.
It includes 14 elements that precede lanthanum from atomic number 58 to 71. Their electron configuration includes 4f and 5d energy levels. Due to the closeness of these two levels, there is uncertainty in some electron configuration. All the elements in this series form +3 ions as their principal chemical species.
The chemical properties are quite similar to one another of lanthanoids. They react with water to liberate hydrogen. Many lantahnoids are mainly used in lasers. A number of lanthanoids like cerium, neodymium and samarium can be alloyed with other metals for making strong permanent magnets.
The electron configuration of actinoids elements are uncertain than the lanthanoids because the closeness of the energy levels. All of the actinoids are unstable with respect to alpha emission. The actinoids have a variety of oxidation states. For example, uranium has compounds in each of the states, +3, +4, +5, and +6.
In nuclear weapon and nuclear reactors, some of the isotopes of uranium and plutonium are used. Apart of this, there are some nuclear reactor designs which involve the use of thorium. In addition, thorium is also used for coating tungsten wiring in electronic equipment. And this technique is termed as uranium-thorium dating, used in determination of the age of carbonate materials and fossils. A minute quantity of americium is also found in smoke detector, which is used to produce ionizing radiation.