Question

The compound has $3{d^2}4{s^2}$ configuration is related to which block:
(A) s-block
(B) p-block
(C) d-block
(D) f-block

Answer 1

Hint : See in which orbitals the last electron goes and compare the configuration with general configuration of each block of periodic table. This configuration resembles ${(n - 1)^x}{n^y}$ .

Complete Step By Step Answer:
Let us analyse each block of the periodic table individually.
s-block of the periodic table comprises group 1 and group 2. It is in the leftmost of the periodic table with only helium in the noble gases. It consists of elements like sodium, hydrogen, magnesium, aluminium, potassium and many more. The alkali metals in s-block consist of only one electron in the s-orbital while alkaline earth metals consist of two electrons in the s-orbital. They are called s-block elements because the last valence electron goes in s-orbital and their general configuration is $n{s^{\left( {1 - 2} \right)}}$ .
p-block of the periodic table ranges from columns 3A to 8A. there are 35 p-block elements. They are called p-block elements because the last valence electron goes in p-orbital and their general configuration is $n{s^2}n{p^{1 - 6}}$ .
d-block of the periodic table ranges from group 3 group 12. Elements of d-block are also called transition metals. They are called d-block elements because the last valence electron goes in d or s-orbital and their general configuration is $(n - 1){d^{1 - 10}}n{s^{1 - 2}}$ .
f-block of the periodic table provides a transition in the sixth and seventh row. Elements of f-block are also called inner transition metals. They are called f-block elements because the last valence electron goes in f-orbital and their general configuration is $(n - 2){f^{0 - 14}}(n - 1){d^{0 - 1}}n{s^2}$ .
The given configuration is $3{d^2}4{s^2}$ and we can see it resembles the general configuration of d-orbital elements.
So option C is the correct answer.

Note :
Transition elements are coloured because they have completely and half-filled d orbitals. They show excellent catalytic properties because of half-filled that is vacant d orbitals. Zinc, cadmium and mercury are not considered transition elements because their orbitals are completely filled in ground state as well as in oxidation states.