Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : The first ionization enthalpy of 3d series elements is more than that of group 2 metals
Reason (R) : In 3d series of elements successive filling of d-orbitals takes place.
In the light of the above statements, choose the correct answer from the options given below :
Assertion (A) : The first ionization enthalpy of 3d series elements is more than that of group 2 metals
Reason (R) : In 3d series of elements successive filling of d-orbitals takes place.
In the light of the above statements, choose the correct answer from the options given below :
- (A)Both (A) and (R) are true and (R) is the correct explanation of (A)✓ Correct
- (B)Both (A) and (R) are true but (R) is not the correct explanation of (A)
- (C)(A) is false but (R) is true
- (D)(A) is true but ( ) is false
Answer: (A)
Solution
The first ionization enthalpies of the 3d-series elements (ScZn, about ) all exceed that of the group-2 metal of the same (4th) period, calcium (); transition metals have higher IE than the adjacent s-block metals, so Assertion (A) is true. Across the 3d series electrons are added successively to inner 3d orbitals, which shield the 4s electrons poorly; the resulting rise in effective nuclear charge is exactly what makes these IEs larger. So Reason (R) is true and is the correct explanation of (A).
JEE Main · 2023 · 31 Jan 2023 · Shift 2 · Single correct option