What distinguishes a transition metal from an inner transition metal?

Transition metals are found in groups 3-12 of the periodic table, while inner transition metals are in the f-block, the lanthanides and actinides.

Transition metals and inner transition metals are both types of elements found on the periodic table, but they are located in different areas and have distinct properties. Transition metals are found in groups 3 through 12 of the periodic table. These metals, which include elements like iron, copper, and gold, are characterised by their ability to form stable, coloured compounds, and their variable oxidation states. They also often act as catalysts in chemical reactions due to their ability to lend and accept electrons easily.

On the other hand, inner transition metals, also known as the f-block elements, are found at the bottom of the periodic table, separated into two series: the lanthanides and the actinides. The lanthanides, also known as rare earth metals, include elements like cerium and europium. The actinides include elements like uranium and plutonium. These elements are characterised by their large atomic and ionic sizes, complex electron configuration, and the presence of f-orbitals in their ground state or common oxidation states.

The key difference between transition metals and inner transition metals lies in their electron configuration and the type of d or f orbitals that are being filled with electrons. For transition metals, the last electron enters the d-orbital, whereas for inner transition metals, the last electron enters the f-orbital. This difference in electron configuration results in different chemical and physical properties. For example, inner transition metals tend to have higher melting and boiling points than transition metals.

In summary, while both transition metals and inner transition metals play crucial roles in chemistry and various industrial applications, they are distinguished by their location on the periodic table, their electron configurations, and their resulting properties. Understanding these differences is key to mastering the complexities of the periodic table and the fascinating world of inorganic chemistry.