Doesn't all the other elemts also have d electrons Why is the answer Ni Q 3 The - Chemistry - The d-and f-Block Elements

Question

Doesn't all the other elemts also have d electrons? Why is the
answer Ni?
Q 3 The element having lowest I E 1
(1) Fe
(2) Co
(3) Ni
(4) Cu
Sol Answer (3)
Ni has the lowest I E 1 value because of the sheilding of 3d
electrons

Bharti Paliwal · Accepted Answer

Dear Student3d-transition series is:Sc  [Ar] 3d14s2Ti   [Ar] 3d24s2V    [Ar] 3d34s2Cr   [Ar] 3d54s1Mn  [Ar] 3d54s2Fe   [Ar] 3d64s2Co   [Ar] 3d74s2Ni    [Ar] 3d84s2Cu   [Ar] 3d104s1Zn   [Ar] 3d104s2Now, from Sc to Mn d-shell is half filled and due to poor shielding effect of d-orbital, nuclear charge effect predominates and ionization enthalpy required is high
But, from Fe onwards d-shell is more than half-flled , i
e  the no
 of electrons in d-orbital are effective to shield the nuclear charge effect to an extent and thus the energy required to remove an electron from the s-orbotal decreases
Therefore, ionistaion enthalpy decreases from Fe to Ni, and Ni has the lowest ionisation enthalpy
Cu being fully filled in 3d and half -filled in 4s require high ionisation enthalpy than Ni
So, the correct option is Nickel Regards

Doesn't all the other elemts also have d electrons? Why is the answer Ni? Q.3. The element having lowest I E 1 (1) Fe (2) Co (3) Ni (4) Cu Sol. Answer (3) Ni has the lowest I E 1 value because of the sheilding of 3d electrons.

Doesn't all the other elemts also have d electrons? Why is the answer Ni?
Q.3. The element having lowest $I E_{1}$
(1) Fe
(2) Co
(3) Ni
(4) Cu
Sol. Answer (3)
Ni has the lowest $I E_{1}$ value because of the sheilding of 3d electrons.