Hi aspirant,

The "transition elements" are those elements which are having a partially filled d or f subshell in any common oxidation state. The term "transition elements" is most commonly refers to the d-block transition elements.

Among lead(Pb), Silver(Ag), Gold (Au) and Tin(Sn), the two elements lead(Pb) and Tin(Sn) are post transition Elements Whereas the remaining two Gold(Au) and Silver(Ag) are transition Elements.

Note: Post-transition metals are a set of metallic elements in the periodic table located between the transition metals to their left, and the metalloids to their right.

Hope it helps you.