Question

deduce which block and period the element cerium belongs to. block period a f 6 b f 7 c d 6 d d 7 a b c d

Explanation:

Cerium (\(Ce\)) has an atomic number of \(58\). Its electron configuration is \([Xe]6s^{2}4f^{1}5d^{1}\). The block of an element is determined by the sub - shell in which the last differentiating electron enters. For cerium, the last differentiating electron enters the \(f\) sub - shell (in the lanthanide series which is part of the \(f\) - block). The period number is equal to the highest principal quantum number (\(n\)) of the electron in the atom. Here, the highest \(n\) value is \(6\) (from the \(6s\) and \(5d\) orbitals; for the purpose of period determination, we consider the highest \(n\)).

Answer:

A. f, 6