(i) Account for the fact that `Eu^(2+)` is a strong reducing agent.
(ii) Why has Zn lowest enthalpy of atomization in 3d series ?

Explanation

(i) `Eu^(2+)` is a strong reducing agent because it changes `Eu^(3+)` by losing as electron, which is comparatively more stable.
(ii) In Zn, metallic bond is weak due to completely filled electronic configuration i.e., `[Ar]4s^(2)3d^(10)`. Therefore,its enthalpy of atomization is the lowest in teh 3d series of elements.