A, B, and C are hydroxy-compounds of the elements X, Y, and Z respectively. X, Y, and Z are in the same period of the periodic table. A gives an aqueous solution of pH less than seven. B reacts with both strong acids and strong alkalis. C gives a strongly alkaline aqueous solution. Which of the following statements is/are true? I: The three elements are metals. II: The electronegativities decrease from X to Y to Z. III: The atomic radius decreases in the order X, Y, and Z. IV: X, Y, and Z could be phosphorus, aluminum, and sodium respectively.

X>>A(hydroxy compound)>> Gives an aqueous solution having pH less than 7 So, X is a non-metal forming an acidic aqueous solution. Y>>B(hydroxy compound)>> Gives an aqueous solution that reacts with both acid and alkali. So, Y is amphoteric in nature. Z>>C (hydroxy compound)>> Gives a strongly alkaline aqueous solution. So, Z is a metal forming a strongly alkaline solution. Hence, the option (c) is the correct answer. As X being non-metal can be phosphorus, Y being amphoteric can be aluminum, and Z being metal can be sodium. And the electronegativity order is X Y Z, accordingly. The order of their