What defines transition metals in the periodic table?

Transition metals are defined by their ability to form variable oxidation states, which is a key characteristic that distinguishes them from other elements in the periodic table. These metals, primarily located in the d-block of the periodic table, can lose different numbers of electrons from their d-orbitals and s-orbitals, resulting in various oxidation states. This property allows for a wide range of chemical reactions and complex formation, particularly in coordination chemistry.

In addition to variable oxidation states, transition metals often exhibit unique properties such as colored compounds and catalytic activity, which are closely tied to their electron configuration and the presence of d-electrons. The flexibility in oxidation states is fundamental to many of their chemical reactions and the diverse compounds they can form.

The other groups mentioned do not align with the defining features of transition metals. Elements primarily found in the s-block or p-block do not typically exhibit the range of oxidation states that transition metals do, and not all transition metals are poor electrical conductors; in fact, many are good conductors. Therefore, the ability to form variable oxidation states is the defining characteristic of transition metals.