The first ionization potential of Na, Mg, A1, and Si are in the order a. Na < Mg > A1 < Si b. Na > Mg > A1 > Si c. Na < Mg < A1 > Si d. Na > Mg > A1 < Si

Sol. Electronegativity increases from left to right in a period and decreases from top to bottom in a group. Variation is more rapid in group than in a period, hence, the desired order is : electronegativity : Si < P < C < N