Given below are two statements: Statement (I) : In the Lanthanoids, the formation of Eu ⁺² is favoured by its half-filled f-orbital configuration. Statement (II) : Eu ⁺² is a strong reducing agent reverting to the common +3 state. In the light of the above statements, choose the most appropriate answer from the options given below:

Step-by-step solution

The electronic configuration of Europium (Eu, Z=63 ) is [ Xe ] 4f⁷ 6s² . When it loses two electrons, it forms Eu ²⁺ with the configuration [ Xe ] 4f⁷ . The half-filled 4f subshell provides extra stability, which favours the formation of the +2 oxidation state. Thus, Statement I is true. Despite the stability of the half-filled configuration, the +3 oxidation state is the most characteristic and thermodynamically stable state for all lanthanoids. Therefore, Eu ²⁺ readily loses one more electron to become Eu ³⁺ , ac