question_answer 18)

What are the characteristics of transition elements and why are they called transition elements? Which of the d-block elements may not be regarded as the transition elements?

Answer:

Transition elements with partly filled d-orbitals exhibit certain characeristic properties. For example, they display a variety of oxidation states, form coloured ions and enter into complex formation with different anions and neutral molecules. These metals and their compounds also exhibit catalytic property and many of them show paramagnetic behaviour. These elements are called transition elements because these represent a transition in properties from s-block elements (most electropositive elements) to p-block elements (least electropositive element). Zn, Cd and Hg do not have incomplete (or partially filled) d-subshell in their elementary as well as in their common oxidation state. Truely speaking, these should not be regarded as transtion elements.