NEET Chemistry Notes The d- and f- Block Elements – d-Block Elements
d-and f-Block Elements
If last electron enters in penultimate (n -1) d-orbital the elements are called d-block elements and if it enters in (n – 2) f-orbital, the elements are called f-block elements.
d-block elements are present from fourth period onwards. There are mainly three series of the transition metals,
- 3d-series (Sc to Zn),
- 4d-series (Y to Cd) and
- 5d-series (La to Hg, omitting Ce to Lu).
d-block elements are known as transition elements because their position in the periodic table is between the s-block and p-block elements.
Electronic configuration of the d-block elements is but Cu+, Zn, Cd,Hg etc.,
are d-block elements, but not transition metals because these have completely filled d-orbitals.