In elements of group 14.
(a) which forms the most acidic oxide
(b) Which is normally found in +2 oxidation state
(c) which is used as semi conductor?

Explanation

(i) As a electronegativity of element decreases from C to Pb, the acidic character of their dioxide also decreases from C to Pb. Thus, C forms the most acidic dioxide i.e., `CO_(2)`.
(ii) Since the inert pair effect becomes more and more predominant does the group, therefore, stability of +2 oxidation state increases down the group. thus, lead is commonly found in +2 oxidation state.
(iii) Silicon and germanium are neither too electronegative nor too electrpositive. Therefore they act as metalloids and hence behave as semiconductors.