Which one of the following is a 'd-block element' ?

Options

A. Gd
B. Hs
C. Es
D. Cs

Answer

B

Explanation

d-block elements have incompletely filled d - orbitals in their ground state or in any of their oxidation states
The general electronic configuration of d - block elements is `(n-1)d^(1-10)ns^(1-2)`. Depending on (n-1) values, there are 3d, 4d, 5d and 6d series of transition elements. Hs(Z=108) [Hassium] belongs to 6d series with electronic configuration `-[Rn]5f^(14)6d^(6)7s^(2)`.