d-block

d-block has 10 group between 2 to 13. And 4 period from 4 to 7.
d-block elements are called transition elements.
In these, the outermost shell containts one or two electrons in their S-orbital but the last electron enters the last but one d-subshell i.e (n -1)d.

the elements of this block have general characteristic properties intermediate between the elements of S-block and p-block.
d-Block elements contain industrially important metals like iron, zinc, cadmium, copper, Titanium, nickel, chromium etc. And also contain silver, gold, and platinum.
the transition elements are those elements which have incompletely filled d-subshell in their ground state or in any one of their oxidation States.
General electronic configuration :- (n-1)d1-10 ns1-3.

First transition series

It contains scandium (Z=21) to zinc (Z=30).
3-d orbitals are gradually filled.
But, Cr or Cu has some different electron configuration like [Ar] 3d5 4s1 and [Ar] 3d10 4s1 instead of [Ar] 3d4 4s2 and [Ar] 3d9 4s2 respectively.

Second transition series

It contain yttrium (Z=39) to cadmium (Z=48).
4d orbitals are gradually filled.
The element technetium (Tc) feature synthetic transition metal which was made artificially.

Third transition series

It contains Lanthanum (Z=57),Hafnium (Z=72) to Mercury (Z=80).
5d orbitals are gradually filled.
In between lanthanum and hafnium there are 14 electrons called lanthanoids which involve in the f-block.

Fourth transition series

Chemical Reaction