Alltransitionelement ared- block elementbut all d- blockelementare nottransition elements Explain.

Alltransitionelement ared- block elementbut all d- blockelementare not

1.	Alltransitionelement ared- block elementbut all d- blockelementare nottransition elements Explain.
Answer» Solution :Elementin whichthe last electron ENTERS any one of the five d- orbitalsof theirrespec tive penultimateshells arecalledd-blockelements. Inthe light of thisdefinition Zn ,CD,Hg and CN cannot beregarded asd- blockelementsincelast electron inthementersthe s-orbital of their respective ultimate shells ratherthan the d- orbital oftheir respectivepenultimate shells . thereforethese elementshouldberegardedas s- BLOCKELEMENT.Butthe propertiesof theseelementresemblemore the d-blockratherthan s- blockelement( referto ANS to Q.1 page `3//61`) . Thereforeto makethe studyof periodicclassification ofelementmorerationalthey arestudied along withd-blockelement. Thuson thebasisof properties alltransitionelementare d-blockelementbut on thebasisof electronicconfigurationall d-blockelementare not a transitionelements