Question

IE₁ of alkaline earth metals are higher than that of alkali metals, but IE₂ of alkaline earth metals are smaller than that of alkali metals. Give reason.

Answer 1

(i). IE₁ of alkaline earth metals > IE₁ of alkali metals. 

(ii). IE₂ of alkaline earth metals < IE₂ of alkali metals. 

(iii). This occurs because in alkali metals the second electron is to be removed from a cation, which has already acquired a noble gas configuration. 

(iv). In the case of alkaline earth metals, the second electron is to be removed from a monovalent cation, which still has one electron in the outermost shell. 

(v). Thus, the second electron can be removed more easily in the case of group 2 elements than in group I elements.