Which element from following is the last element of 5d-transition series?

Step-by-step solution

The 5d transition series consists of the elements from Lanthanum (La, atomic number 57) to Mercury (Hg, atomic number 80). This series comprises a portion of the d-block elements, specifically those wherein the d-electron shell is being filled progressively. ( H g ) (Mercury) is the last element of this series, with an atomic number of 80. Its electron configuration is ([X e] 4 f¹⁴ 5 d¹⁰ 6 s^2 ). Elements in the 5d series span across the periodic table and are found prominently in groups commonly referred to as the