Given below are the two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).…
Given below are the two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): There is a considerable increase in covalent radius from to . However from to only a small increase in covalent radius is observed.
Reason (R): covalent and ionic radii in a particular oxidation state increases down the group.
In the light of the above statement, choose the most appropriate answer from the options given below:
(A) is false but (R) is true
Both (A) and (R) are true but (R) is not the correct explanation of (A)
(A) is true but (R) is false
Both (A) and (R) are true and (R) is the correct explanation of (A)
Solution
There is a considerable increase in covalent radius from to . However, from to only a small increase in covalent radius is observed. This is due to the presence of completely filled d and/or f orbitals in heavier members.
As going down in a group, the number of shells increases, hence the covalent and ionic radii increases.
Both (A) and (R) are true but (R) is not the correct explanation of (A)
But the correct explanation is the presence of completely filled d and f-orbitals of heavier members.