Which group of metals is classified as transition metals?

Transition metals are defined as the elements found in groups 3 to 12 of the periodic table. These metals are characterized by their ability to form variable oxidation states and to create complex ions. They typically have partially filled d orbitals, which allow them to exhibit unique properties such as catalytic activity, the ability to form colored compounds, and varying magnetic properties.

The grouping from 3 to 12 encompasses well-known transition metals like iron, copper, and gold. These elements play crucial roles in many chemical reactions, particularly in coordination chemistry and catalysis, which are foundational concepts in analytical chemistry.

In contrast, the other groups mentioned do not fall under the definition of transition metals. Group 1 and 2 metals are more reactive alkaline and alkaline earth metals, while groups 13 to 16 include metalloids and post-transition metals. Lanthanides and actinides are a separate category of rare earth and radioactive elements that are placed in the f-block of the periodic table, thus not included in the transition metal classification. The identification of transition metals is essential for understanding their applications in analytical techniques and industrial processes.