471 × 10–19
Rationalised 2023-24
The d-block of the periodic table contains the elements
of the groups 3-12 in which the d orbitals are
progressively filled in each of the four long periods The f-block consists of elements in which 4 f and 5 f
orbitals are progressively filled They are placed in a
separate panel at the bottom of the periodic table The
names transition metals and inner transition metals
are often used to refer to the elements of d-and
f-blocks respectively