D and F Block Elements

D AND F BLOCK ELEMENTS

The elements lying in the middle of periodic table belonging to groups 3 to 12 are known asd– block elements.

Features of d-block elements:

• The general electronic configuration ofd-block elements is (n−1)d^1─10ns^1─2, where (n−1) stands for the inner d orbitals.

• Ind-block, each horizontal row consists of ten elements asd-subshell can accommodate a maximum of 10 electrons.

• Thed-block elements having incompletely filledd-subshell are called transition metals.

• Zinc, cadmium, mercury having the general electronic configuration as (n–1)d¹⁰ns², are not regarded as transition metals due to completely filledd– orbital.

• There are mainly three series of the transition metals:

3dseries starts with Sc (Z = 21) and ends with Zn (Z = 30)

4dseries starts with Y (Z = 39) and ends with Cd (Z = 48)

5dseries starts with La (Z = 57) and ends with Hg (Z = 80)